JP2013175771A - Method for peeling and removing dicing surface protection tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for peeling and removing a protection tape which is bonded to a surface of an object to be cut and cut together with the object in a dicing process.SOLUTION: A method for peeling and removing a dicing surface protection tape of the present invention comprises the steps of: bonding the dicing surface protection tape to an object to be cut; cutting the dicing surface protection tape and the object to be cut together in a state where the dicing surface protection tape is bonded to the object to be cut; and giving a stimulus for causing contraction to the dicing surface protection tape which is bonded to the surface of the cut object to allow the dicing surface protection tape to wind spontaneously, so as to form a cylindrical wound body, in one direction from an end thereof or from two opposing ends thereof to the center, bonding a peeling tape to each cylindrical wound body which is bonded to the surface of each cut object, and removing the peeling tape together with the cylindrical wound body.

Description

  The present invention relates to a tape for protecting a surface of a material to be cut (for example, a circuit forming surface in the case of a semiconductor wafer) in a process of dicing a material to be cut including a semiconductor wafer. The present invention relates to a surface protection tape for dicing that is diced in a state of being affixed to the surface, and a method for removing the same.

  In a wafer singulation process (hereinafter referred to as dicing process) performed after the back grinding process, the conventional wafer circuit formation surface is exposed. Accordingly, it is assumed that the circuit forming surface is contaminated with cutting water during dicing, dust such as cutting scraps generated by wafer cutting, and the exposed electronic component surface. Such contamination can cause defects. In this case, it is considered to protect the electronic component from dust such as cutting scraps by attaching a protective tape to the circuit forming surface of the wafer and dicing the wafer and the protective tape together. However, the conventional protective tape has not been put into practical use because it is difficult to peel and remove the protective tape from individual wafers.

  Furthermore, in recent years, there is a growing demand for thinner and lighter materials for semiconductors. The semiconductor silicon wafer needs to be thinned to a thickness of 100 μm or less, but such a thin film wafer is very brittle and easily broken. For this reason, the difficulty of peeling / removing the protective tape from the separated wafer is further increased. Therefore, as a method for peeling off the protective tape, a method of peeling the protective tape from the adherend simultaneously with peeling of the peeling tape, a method of peeling off with the force by blowing air, and the like can be considered. ing.

  Japanese Patent Application Laid-Open No. 2003-197567 describes a method for preventing contamination from cutting water, cutting scraps, and the like by attaching a protective tape to a circuit forming surface of an electronic component surface before dicing. A method is described in which the protective tape is contracted and then removed by applying air or applying an external force to the peeling tape by applying an external force to the peeling tape to peel off the protective tape.

  Furthermore, JP-A-2006-196823 describes a method of using a polyolefin film as a protective tape base material, heat-shrinking the base material by heating at the time of removal, and making the removal easy by warping the protective tape. Yes.

  However, the deformation of the protective tape usually caused by shrinkage, particularly heat shrinkage, not only warps, but also causes random deformation such as crumpling. As a result, for example, when the sheet is crumpled, shear stress acts at the interface between the protective tape pressure-sensitive adhesive and the adherend (chip), and the glue is torn off to contaminate the surface of the adherend. In addition, if the adherend is thin and has low rigidity, such as a back-ground semiconductor wafer, the adherend is damaged.

  Furthermore, as shown in FIG. 12, the protective tape that causes random deformation of the shape is not sufficiently peeled off from the adherend, and is not completely removed even when it is exposed to air, and the blow-off residue tends to occur. Further, when the peeling tape is used, since the protective tape is deformed in a random shape, the height of lifting from the adherend is not constant, and the adhesive tape is peeled off. Further, it is conceivable that when an external force is applied to the peeling tape after the peeling tape is bonded, the surface of the adherend is contaminated or damaged. Even when peeling off with tweezers or the like, there are some which do not have a pinch trigger part, and it takes a long time to remove.

  If there is no trigger for peeling off the protective tape, it is difficult to peel off the protective tape by the above method. That is, in order to peel off the protective tape from the adherend, a peeling trigger is required. Therefore, there is a need for a protective tape that can be easily peeled off. Protect the tape by peeling the protective tape by applying a stimulus that causes shrinkage, such as heating, or by using a protective tape with a shrink layer and a constraining layer laminated. A method of creating a trigger for peeling off the protective tape by voluntarily winding the tape by applying a stimulus that causes shrinkage such as heating can be considered.

In the former method, a high temperature condition is required in order to create a peeling trigger. The peeling process under high temperature conditions has the following problems.
1. 1. Damage to electronic components 2. Damage to the dicing tape Contamination of the adherend from the protective tape

  In addition, it takes a lot of time to remove the protective tape from all the chips that have been singulated, and at the same time, the chip may be damaged by the stress at the time of peeling. There is. For this reason, in order to be useful in practice, it is necessary to control the deformation due to the application of a stimulus that causes contraction such as heating so as not to cause the above-described problems.

JP 2003-197567 A JP 2006-196823 A

The object of the present invention is to attach a surface protection tape to the surface of the object to be cut in the dicing process, and cut the surface of the object to be cut from the contamination due to adhesion of dust such as cutting scraps. An object of the present invention is to provide a surface protection tape for use in a dicing process that protects and is easily peeled and removed from individual chips after the dicing process.
Another object of the present invention is to provide a method for peeling and removing a protective tape that is affixed to the surface of a workpiece and cut together with the workpiece in a dicing step.

  The present inventors considered that an adhesive sheet (protective tape) imparted with an easily peelable function was necessary to achieve the above object. When the work of peeling the pressure-sensitive adhesive sheet from the adherend is performed manually, the tape is first picked up at the end of the adherend, and then the tape is pulled and peeled off in order to create a trigger for peeling. However, do not pick up the tape with a weak adherend, and do not damage the adherend by minimizing the peel stress by rubbing the tape, that is, by increasing the peel angle as much as possible. Often, it makes a peeling trigger. Thereafter, the pressure-sensitive adhesive sheet can be peeled from the fragile adherend by peeling the tape so as to maintain the largest peel angle as possible.

  Therefore, the present inventors, when imparting easy peelability by applying a stimulus that causes shrinkage such as heating, as a shape at the time of tape peeling, if it can be deformed as if the carpet is wound (hereinafter, like this The deformed one is referred to as a “cylindrical winding body”), and it was considered to be a protective tape meeting the purpose. This is because peeling while causing such deformation means that the peel angle in peeling is kept as large as possible, and the peeling stress on the adherend is minimized. That is, it means that the possibility of damaging a fragile adherend can be minimized. Furthermore, since the peeling stress is small, the possibility that the pressure-sensitive adhesive is peeled off to the adherend is reduced, so that the possibility that the adherend is contaminated by peeling can be reduced. Even if the wafer is adhered to a member on the wafer polishing surface side, the peeling stress can be minimized, so that the possibility of damaging the wafer is reduced.

  Then, the use of the material which forms a cylindrical wound body to the surface protection tape used at a dicing process by giving the stimulus which causes shrinkage, such as a heating, was examined. As a result, a laminate in which a constraining layer that constrains the shrinkage of the shrinkable film layer is laminated on a shrinkable film layer that shrinks preferably at least 5% or more in one axial direction by applying a stimulus that causes shrinkage such as heating. It has been found that by using as a protective film, the protective tape can be easily peeled off from the adherend and removed.

  When a stimulus that causes shrinkage such as heating is applied to the protective tape, the shrinkage force of the shrinkable film layer and the repulsive force against the shrinkage force of the shrinkable film layer in the constraining layer serve as the driving force, and the outer edge portion (end portion) 1) or 2 cylinders by voluntarily winding in one direction from the end or from the opposite two ends toward the center (center of the two ends) with the shrinkable film layer side inward A wound body can be formed, and the protective tape can be easily peeled off from the adherend and removed. The constraining layer is more preferably composed of a laminate of an elastic layer and a rigid film layer.

  Further, a re-peelable pressure-sensitive adhesive sheet provided with a pressure-sensitive adhesive layer on the surface of the constraining layer side of such a laminated sheet is affixed to the adherend, and after the predetermined roles such as fixing and protecting the adherend are finished, At the time of the disappearance of the adhesive strength of the pressure-sensitive adhesive layer at the time of peeling, when applying heat that promotes the shrinkage of the shrinkable film layer, the outer edge (end) is lifted in the same manner, with the shrinkable film layer side inside, Forming one or two cylindrical wound bodies by horizontal self-propelling while spontaneously winding toward the center (center of the two ends) from the two ends facing one direction from the ends, Therefore, it has been found that the adhesive sheet can be peeled off from the adherend very easily and cleanly without damaging the adherend due to stress at the time of peeling. Furthermore, it has also been found that this shape greatly reduces adherend contamination due to peeling.

  In the present invention, based on these findings, by further research, using a tape in which a shrink layer and a constraining layer are laminated, the tape is given a stimulus that causes shrinkage, and preferably the tape is heated at a low temperature. In this way, the film was voluntarily wound to create a peeling trigger and succeeded in easily performing the peeling removal process.

  That is, the present invention is for dicing in which a shrinkable film layer having shrinkability in at least one axial direction attached to the surface of a workpiece is laminated with a constraining layer that restrains the shrinkage of the shrinkable film layer. A step of affixing a surface protection tape, a step of cutting the dicing surface protection tape and the object to be cut together in a state where the surface protection tape for dicing is affixed, and the cut surface of the object to be cut The above-mentioned dicing surface protective tape affixed to the surface is given a stimulus that causes contraction, and is wound spontaneously from one end to one direction or from two opposite ends toward the center to form a cylindrical wound body. And a step of attaching a release tape to the cylindrical wound body that is formed and affixed to the surface of each cut object, and removing the release tape together with the cylindrical wound body. That features It provides a peel removal method for dicing surface protection tape to be.

  After the surface protection tape for dicing on all cut objects to be cut is deformed into a cylindrical wound body, the release tape may be removed together with the cylindrical wound body, or the cut workpiece You may remove the said peeling tape with the said cylindrical winding body, after transforming the surface protection tape for dicing on a part of to-be-cut body into a cylindrical winding body among cutting bodies.

  It is preferable to affix the said peeling tape on the said cylindrical winding body affixed on each cut | disconnected to-be-cut | disconnected body surface with a hand roller.

  It is preferable that the peeling angle of the peeling tape is 110 to 180 degrees, and the peeling tape is removed together with the cylindrical wound body.

  It is preferable that the peeling point moving speed of the peeling tape is 10 to 350 mm / min and the peeling tape is removed together with the cylindrical wound body.

  The stress required for rewinding the cylindrical wound body formed by heating at 80 ° C. for 30 seconds is preferably 1.3 N / 10 mm or more.

  The surface protective tape of the present invention is attached to the surface of the object to be cut, cut together with the object to be cut, and then energized by applying a stimulus that causes contraction, and the end (one end or opposite) 2) to the main contraction axis direction, usually peeling from the adherend while voluntarily winding to form a cylindrical wound body, which may damage the adherend or cause incomplete peeling It can be removed very easily from the surface of the adherend without contaminating the adherend. For this reason, it is useful as a surface protective tape that is adhered to a particularly fragile adherend. Since the surface protection tape of the present invention can be easily peeled and removed from the adherend, the surface of the object to be cut is protected from contamination due to adhesion of dust such as cutting scraps in the dicing process. It can be easily peeled and removed from the chip.

It is the schematic which shows an example of the surface protection tape of this invention, and the peeling method using the same. It is the schematic which shows another example of the surface protection tape of this invention, and the peeling method using the same. It is a schematic sectional drawing which shows the laminated body 10 of an example of the surface protection tape of this invention. It is a schematic sectional drawing which shows the laminated body 11 of an example of the surface protection tape of this invention. It is a schematic sectional drawing which shows the laminated body 12 of an example of the surface protection tape of this invention. It is a schematic sectional drawing which shows the laminated body 13 of an example of the surface protection tape of this invention. It is a schematic sectional drawing which shows the laminated body 14 of an example of the surface protection tape of this invention. It is a schematic sectional drawing which shows the laminated body 15 of an example of the surface protection tape of this invention. It is the schematic which shows an example of a mode that the surface protection tape of this invention winds spontaneously. It is the schematic which shows an example of a mode that the surface protection tape of this invention is affixed to a to-be-adhered body, and is spontaneously wound, after being diced together with this to-be-adhered body. It is a figure which shows an example of the flow of chip | tip formation using the surface protection tape of this invention. It is the schematic which shows peeling of the surface protection tape of a prior art example.

  The surface protection tape of the present invention is used in a dicing process, is affixed to the surface of a workpiece, and is cut together with the workpiece. The surface protection tape of the present invention has a shrinkable film layer having shrinkability in at least one axial direction and a constraining layer for restraining the shrinkage of the shrinkable film layer, and by applying a stimulus that causes shrinkage such as heating. It peels spontaneously from the surface of the object to be cut. The surface protection tape of the present invention is wound by voluntarily winding from one end to one direction or from two opposite ends toward the center after applying a stimulus that causes contraction, or one or two cylindrical windings. While forming the body, it is peeled off from the object to be cut.

  In addition, in this specification, the cylindrical wound body is not limited to one in which both ends of the tape overlap and are completely wound in a cylindrical shape, but in a state where both ends of the tape are separated without overlapping. Including a shape in which a part of the tape is open, and preferably, the tape is wound into a completely cylindrical shape with both ends thereof overlapping.

  The surface protection tape after winding has drawn the arc, and is in the state which contact | connects the to-be-cut body surface, for example with one line. In addition, in this specification, “spontaneous winding” means that the tape is naturally peeled off from the adherend without using a hand or the like just by giving the tape a stimulus that causes contraction, For example, it means that a peeling trigger is obtained.

  Examples of the object to be cut include semiconductor wafers, glass, ceramics, resin for sealing semiconductors, etc., which have been conventionally subjected to the dicing process, and semiconductor wafers such as 8-inch silicon mirror wafers are preferably used. . The size of the object to be cut is preferably 10 mm × 10 mm or less.

  In the surface protection tape of the present invention, preferably, one or two cylindrical wound bodies are formed by spontaneously winding from one end to one direction or from two opposite ends toward the center by heating. While peeling from the object to be cut.

  The temperature at which the film is spontaneously peeled is not particularly limited as long as the upper limit temperature is a temperature at which the object to be cut is wound without being affected, for example, 50 ° C. or higher, preferably 50 ° C. to 180 ° C., More preferably, it can be set to 70 to 180 ° C.

  In the surface protection tape of the present invention, preferably, the constraining layer is composed of an elastic layer on the shrinkable film layer side and a rigid film layer on the opposite side of the shrinkable film layer. The surface protection tape of the present invention preferably further has an adhesive layer, and the adhesive layer preferably contains an active energy ray (for example, UV) curable adhesive.

  As the surface protective tape, a laminate of a shrinkable film layer / constraint layer is used, and preferably a laminate of a shrinkable film layer / elastic layer / rigid film layer / adhesive layer (hereinafter referred to as these). May be referred to as a self-winding tape). With this configuration, the contraction stress is converted into a couple, and the tape is surely deformed into a cylindrical wound body after application of a stimulus that causes contraction, so that the tape removal in the subsequent peeling step becomes extremely simple. The details of the material constituting the tape may be in accordance with Japanese Patent No. 4151850. Specifically, the tape is preferably a laminate (spontaneous winding tape) composed of a shrinkable film layer / elastic layer / rigid film layer / adhesive layer.

  The method for peeling and removing a surface protective tape according to the present invention includes a shrinkable film layer having shrinkage in at least one axial direction attached to a surface of a cut object, and a constraining layer for restraining shrinkage of the shrinkable film layer. A dicing surface protection tape laminated, a dicing surface protection tape being affixed, a step of cutting the object to be cut, and a surface of the cut object to be cut The dicing surface protective tape is given a stimulus that causes shrinkage, and is wound spontaneously from one end to one direction or from two opposite ends toward the center, and one or two cylindrical wound bodies And removing the dicing surface protective tape attached to the cut surfaces of the individual cut objects.

  After this tape is bonded to the adherend, dicing is performed. As a dicing apparatus / method, a conventionally known method may be used, and there is no limitation by using this tape. When the adherend is a semiconductor wafer, the back grinding process may be performed after the tape is bonded to the adherend, and the dicing process may be performed without removing the tape as it is.

  In the method for peeling and removing the surface protective tape of the present invention, preferably, the stimulus that causes the shrinkage is heating. Preferably, the method further includes a step of irradiating active energy rays before or simultaneously with the heating.

  After dicing, the conventional method (when there is no protective tape) enters the process (pickup) of collecting the diced adherend, but in the method of peeling and removing the surface protective tape of the present invention, for example, before picking up or after picking up A step of peeling and removing the tape (peeling / removing step) is performed by applying a stimulus that causes shrinkage such as heating to the tape.

  The peeling / removal step includes: a. Performing UV irradiation (if the adhesive layer is a UV curable adhesive); b. Applying a stimulus that causes contraction to transform the tape into a cylindrical roll; and c. The method includes a step of removing the deformed tape from the adherend, and preferably proceeds in the order of a, b, and c. These steps may be performed simultaneously.

The method a may be a conventionally known method, and a high pressure mercury lamp, a xenon lamp, an ultraviolet LED, or the like is used as a light source, and light in the UV wavelength region may be irradiated to the tape at about 500 to 1000 mJ / cm ^2. .

  As a method of applying a stimulus that causes contraction of b, heating can be preferably performed. For the heating, for example, a heating source such as a hot plate, a heat gun, or an infrared lamp can be used. Appropriate methods are selected and used so that the temperature is reached quickly. The heating temperature is not particularly limited as long as the upper limit temperature is a temperature at which the object to be cut is wound without being affected, for example, 50 ° C. or higher, preferably 50 ° C. to 180 ° C., more preferably 70 ° C. It can be set to ℃-180 ℃. In addition to applying the stimulus that causes the shrinkage uniformly, all tapes may be deformed at once, or may be performed in a spot manner, for example, by partially heating at an arbitrary position using a spot heating device or the like. A method of deforming may be used.

  Examples of the method c include a method using a peeling tape, a method in which a tape that has been deformed by blowing air is blown off, and suction by a vacuum cleaner. In addition, a large effect can be obtained even by hand picking up with tweezers. In addition, when using a peeling tape, it is necessary to devise a bonding method so that the peeling tape does not contact the surface of the adherend (see Examples described later).

  The peeling process is preferably a heating process using a heating device / method (hot plate, heat gun, etc.) for deforming the tape, and a protective tape removing method after heating (blowing, sucking, attaching a peeling tape, etc.) ) Using a removal step. Preferably, in the heating step, heating is performed using any one of a hot plate, a heat gun, an infrared lamp, or a combination thereof.

  Preferably, in the removing step, the surface protection tape is removed by any one of adhesion by a peeling tape, blowing off by wind, suction removal by suction, or a combination thereof. The suction removal is preferably performed using a vacuum cleaner.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing an example of the surface protection tape 1 of the present invention and a peeling method using the same. Hereinafter, description will be given with reference to FIG.

<Preparation of sample for dicing>
As shown in FIG. 1, the surface protection tape 1 is affixed to the adherend 7 such as a wafer to produce a laminate. Examples of the adherend 7 include those that have been conventionally subjected to a dicing process, such as semiconductor wafers, glass, ceramics, and semiconductor sealing resins. The attachment of the surface protection tape 1 to the adherend 7 such as a wafer is not particularly limited, and can be applied using a hand roller, for example.

  As the adherend 7, a semiconductor wafer such as an 8-inch silicon mirror wafer is preferably used. When a semiconductor wafer is used as the adherend, the adherend in the laminated body may be subjected to processing such as back grinding so that the adherend has a predetermined thickness. When the adherend is a semiconductor silicon wafer, a silicon wafer having a thickness of several tens to several hundreds of μm can be used, and in particular, an extremely thin silicon wafer having a thickness of 100 μm or less can also be used.

  Next, the adherend 7 side of the laminate of the surface protection tape 1 and the adherend 7 is attached to the dicing tape 8, and the laminate of the surface protection tape 1, the adherend 7, and the dicing tape 8 To do. The dicing tape 8 is not particularly limited, and a known dicing tape can be used. This laminate is designated as a sample 9 for dicing. You may affix this laminated body to the dicing ring 19 further. The dicing ring 19 may not be used. A method for attaching the laminate of the surface protective tape 1, the adherend 7 and the dicing tape 8 to the dicing tape 8 is not particularly limited, and for example, it can be attached using a hand roller.

<Dicing>
Subsequently, the sample 9 for dicing is diced. Dicing can be performed using a known dicing apparatus, and can be performed by blade dicing, laser dicing, or the like. Dicing may be performed while applying water. The amount of cutting water is not particularly limited, and can be set to 1 L / min, for example. By dicing, the sample 9 is formed into a chip shape such as 5 mm × 5 mm or 10 mm × 10 mm.

  In the case of blade dicing, the dicing speed and blade rotation speed can be arbitrarily set depending on the material, thickness, etc. of the adherend 7. When the adherend 7 is a silicon wafer, the dicing speed can be, for example, 60 to 100 mm / sec, preferably 70 to 90 mm / sec, and the blade rotation speed can be, for example, 30000 to 50000 rpm, preferably 35000 to 45000 rpm. can do. The blade height can be arbitrarily set within a known range.

  When the surface protection tape 1 of the present invention is attached to the adherend 7, it can be cut together with the adherend 7. Since the surface protection tape 1 can be reliably affixed to the adherend 7, it is possible to prevent the protection tape from jumping during dicing.

  The laminate of the surface protection tape 1 and the adherend exhibits good dicing properties, and wafer chipping or cracking occurs, or water during dicing enters the interface between the surface protection tape 1 and the adherend 7. Without doing so, a chip in which the surface protection tape 1 and the adherend 7 are laminated can be obtained.

<Applying stimulus that causes contraction>
The surface protection tape 1 of the present invention is wound by the application of a stimulus that causes contraction such as heat and is spontaneously peeled off from the adherend 7. In FIG. 1, heating is performed as an example regarding a stimulus that causes contraction, but is not limited to heating. As shown in FIG. 1, when a stimulus that causes shrinkage such as heating is applied to a chip obtained by dicing, the surface protection tape 1 is deformed to form an arc, thereby forming a wound body 1 ′. The contact point between the wound body 1 'and the adherend 7 is smaller than other arbitrary shapes obtained by deforming other conventional release liners, and preferably has a cylindrical shape. For this reason, the contact point between the wound body 1 ′ and the adherend 7 is, for example, only one line.

  The heating time for peeling off the surface protection tape 1 is arbitrary and is not particularly limited. However, from the viewpoint of protecting the adherend 7, a timing that is as late as possible and that requires peeling is preferable.

  When the surface protection tape 1 of the present invention is wound spontaneously, for example, by heating, it is surely generated with good reproducibility by selecting predetermined conditions for the heating temperature, tape configuration, etc., and reliably peeled off from the adherend 7. Can be made. Therefore, there is no peeling of the surface protection tape.

  Giving a stimulus that causes shrinkage, such as heating, to the surface protection tape, the entire surface of the adherend may be stimulated uniformly as necessary when performing the peeling operation, and the entire surface is stimulated stepwise. Partial stimulation may be used only to create an exfoliation trigger. For example, the heating temperature and the heating time of the pressure-sensitive adhesive sheet can be appropriately adjusted according to the shrinkability of the heat-shrinkable substrate used, and can be set to a temperature at which the surface protective tape is spontaneously peeled off. The heating time is, for example, about 5 to 600 seconds, preferably about 5 to 300 seconds, and more preferably about 5 to 180 seconds.

  Although it does not specifically limit as a heating method, Heat sources, such as a hot plate, a heat gun, an infrared lamp, can be illustrated. For example, in the heating by the hot plate, the surface protection tape on all the chips on the hot plate is spontaneously wound at the same time. For example, when heating with a heat gun, local chip heating is also possible, so only the surface protection tape on some chips can be wound spontaneously as needed.

  The heating temperature of the surface protection tape 1 is not particularly limited as long as the upper limit temperature is a temperature at which the object to be cut is wound without being affected, for example, 50 ° C. or more, preferably 50 ° C. to 180 ° C. More preferably, it can be set to 70 ° C to 180 ° C. When the heating temperature is lower than 50 ° C., the surface protection tape 1 cannot be deformed sufficiently for peeling or does not rapidly deform. Moreover, when heating temperature is too high, malfunctions, such as a failure | damage of the to-be-adhered body 7, will arise.

  The size of the diameter r of the arc drawn by the wound body 1 ′ formed by voluntarily winding is determined by, for example, the heating conditions such as the heating temperature and the amount of hot air, the composition and configuration of the surface protection tape 1, etc. It can be adjusted as appropriate. That is, the winding condition of the wound body 1 ′ is preferably determined by conditions such as heating conditions and the structure of the surface protection tape 1. The smaller the diameter r, the stronger the degree of winding. The surface protective tape 1 is preferably deformed into a cylindrical wound body by heating.

  For example, the wound body 1 ′ is formed due to the heat shrinkage stress of the shrinkable base material, and the development of the shrinkage stress is a thermally irreversible process (it does not return to the non-shrinkable state even if reheated). Once wound, it will not unwind itself even if heating is continued, and it will not be easily unwound by stress due to the high elasticity of the shrinkable and rigid substrates after heating. Hold. For this reason, it does not collapse or expand easily.

  For example, in the case of the laminated body of FIG. 4, FIG. 8, etc., it is estimated that, for example, a stress of 1.3 N / 10 mm or more is required to rewind the wound body heated at 80 ° C. for about 30 seconds. Further, in order to compress the diameter of the wound body 1 ′ having a width of 10 mm to about 1/3, for example, a load of 250 g to 300 g is necessary, and when the load disappears, the diameter of the wound body almost returns to the initial state. . Furthermore, as described above, the winding condition of the wound body 1 ′ can be determined by setting conditions. Due to the conditions, the individual chips exhibit substantially the same shape.

  The surface protective tape 1 may include a UV curable adhesive. In this case, UV irradiation can be performed before applying a stimulus that causes contraction such as heating for spontaneous winding of the surface protective tape 1. UV irradiation may be performed simultaneously with the application of the stimulus.

  Further, the application of the stimulus may be performed after picking up the separated chip. FIG. 2 shows an example of a peeling method in which the surface protection tape is heated after picking up and the tape is peeled and removed.

<Removal>
Examples of a method for removing the wound body 1 ′ obtained by deforming the surface protection tape 1 from the adherend 7 include the following methods.
(I) A method of peeling with a peeling tape.
(Ii) How to blow away.
(Iii) A method of peeling with tweezers.
(Iv) A method of removing by suction.

  The removal may be performed after the surface protection tape on all the chips is transformed into the wound body 1 ′, and the surface protection tape on a part of the chip is transformed into the wound body 1 ′. Things may be done sequentially.

  In the method (i) of peeling with the peeling tape, the peeling tape is attached to the wound body 1 ′ generated by applying a stimulus that causes shrinkage such as heating of the surface protective tape 1, and removed together with the peeling tape. Affixing of the release tape to the wound body 1 'can be performed with a hand roller, for example.

  In this case, in the wound body 1 ′ in which the surface protection tape 1 of the present invention is thermally deformed, the wound body 1 ′ in each chip exhibits substantially the same shape. The height from the surface of the body is constant. In addition, each wound body 1 ′ has rigidity, does not easily deform, and once wound, does not unwind due to stress and maintains a certain shape. Therefore, even if the peeling tape is adhered to the wound body 1 ′ with a certain amount of stress using a hand roller or the like, the possibility of coming into contact with the adherend 7 is low. Therefore, the release tape can be adhered to all the wound bodies 1 ′ without leakage. As a result, the surface protective tape 1 can be removed cleanly and efficiently without leakage. In addition, it does not specifically limit as a peeling tape, A well-known peeling tape can be used.

  The peeling angle of a peeling tape can be 110-180 degree, for example, Preferably it can be 115-175 degree. The peeling point moving speed can be, for example, 10 to 350 mm / min, preferably 155 to 325 mm / min.

  In the blowing method (ii), the wound body 1 ′ formed on the adherend 7 can be removed by blowing using a wind power generation medium and blowing off the wound body 1 ′. The surface protective tape 1 of the present invention is reliably deformed by applying a stimulus that causes contraction such as heating in a separated state after dicing, and becomes a wound body 1 ′ having substantially the same shape, In this chip, it is preferable to contact the adherend 7 only with one line. For this reason, it can be easily removed with relatively weak wind power.

  As the wind power generation medium, a dryer, a fan, or the like can be used. The removal by the blowing method may be performed with air at normal temperature, for example, with warm air or hot air after the surface protection tape 1 is heated in advance to form the wound body 1 ′.

  Further, the removal by the blowing method may be performed while forming the wound body of the surface protection tape 1 by heating or the like. In this case, hot air can be used. The temperature of the hot air can be determined such that the surface temperature of the surface protection tape 1 is 80 ° C to 100 ° C, for example.

  Blowing can be performed with respect to the adherend 7 at an angle of 40 to 50 degrees, for example. The blowing time is not particularly limited, but may be, for example, 1 minute to 5 minutes, preferably 2 minutes to 4 minutes.

  Further, the removal of the surface protection tape 1 by the blowing method (ii) may be performed while the adherend 7 and the wound body 1 ′ are supplementarily heated by a heating medium such as a hot plate. In this case, the auxiliary heating temperature by the heating medium can be set to 50 ° C. to 70 ° C., for example.

  In the method of peeling with the tweezers (iii), the wound body 1 ′ with the deformed surface protection tape 1 is pinched with tweezers and removed. The surface protective tape 1 of the present invention is deformed reliably by applying a stimulus that causes contraction such as heating in the state of being separated into pieces after dicing, and becomes a wound body 1 ′ having substantially the same shape, In the chip, preferably, it is in contact with the adherend 7 only at one line. For this reason, it can be easily removed with a relatively weak force.

  The wound body 1 ′ in which the surface protection tape 1 of the present invention is thermally deformed has rigidity, does not rewind, and has a fixed shape. Therefore, the wound body 1 ′ is easily removed by tweezers and can be removed quickly. In addition, the wound body 1 ′ deformed by applying a stimulus that causes the surface protection tape 1 of the present invention to contract such as heating draws an arc, so that the contact point with the adherend 7 is, for example, one line. Only and very small. Therefore, it is easily detached from the adherend 7 with a small stress. This method is particularly useful for fragile and expensive adherends such as extremely thin wafers.

  In the method of suction removal by suction (iv), the wound body 1 ′ formed on the adherend 7 is removed by sucking using a suction medium and sucking the wound body 1 ′. The surface protective tape 1 of the present invention is deformed reliably by applying a stimulus that causes contraction such as heating in the state of being separated into pieces after dicing, and becomes a wound body 1 ′ having substantially the same shape, In the chip, preferably, it is in contact with the adherend 7 only at one line. For this reason, it can be easily removed with a relatively weak force.

  A vacuum cleaner or the like can be used as the suction medium. The removal by the suction removal method by the suction may be performed after the surface protective tape 1 has been given a stimulus that causes shrinkage such as heating in advance to form the wound body 1 ′. It may be performed simultaneously while forming a wound body by heating or the like.

  Further, the removal of the surface protection tape 1 by the suction removal method (iv) may be performed by preheating the adherend 7 and the wound body 1 ′ with a heating medium such as a hot plate. In this case, the preheating temperature by the heating medium can be set to 50 ° C. to 70 ° C., for example.

[Surface protection tape]
In FIG. 3, the schematic sectional drawing of the laminated body 10 of an example of the surface protection tape of this invention is shown. For example, as shown in FIG. 3, the surface protection tape 1 can be a laminate 10 of a shrinkable film layer 2 and a constraining layer 3. The shrinkable film layer 2 preferably has uniaxial shrinkage. The constraining layer 3 functions as a layer that constrains the shrinkage of the shrinkable film layer 2.

  FIG. 4 is a schematic sectional view showing a laminate 11 as an example of the surface protection tape of the present invention. FIG. 5 is a schematic sectional view showing a laminate 12 as an example of the surface protection tape of the present invention. A laminate 11 shown in FIG. 4 is a laminate of a shrinkable film layer 2 having uniaxial shrinkage and a constraining layer 3 that restrains shrinkage of the shrinkable film layer 2.

  The shrinkable film layer 2 may be any film layer that is shrinkable in at least one axial direction, and may be any of a heat shrinkable film, a film that exhibits shrinkage by light, a film that shrinks by electrical stimulation, and the like. It may be. Especially, it is preferable that it is comprised with the heat-shrinkable film from viewpoints, such as working efficiency.

  The constraining layer 3 includes an elastic layer 31 on the shrinkable film layer 2 side and a rigid film layer 32 on the opposite side of the shrinkable film layer 2. Moreover, in the laminated body 12 shown by FIG. 5, the adhesive layer 4 is laminated | stacked on the rigid film layer 32 side of the laminated body 11 shown by FIG. In this case, the laminated body 11 of FIG. 4 functions as a support base material of the laminated body 12 of FIG.

  Furthermore, the schematic sectional drawing of the laminated body 13 of an example of the surface protection tape of this invention is shown in FIG. In the laminate 13, the release liner 5 is laminated on the opposite side of the rigid film layer of the pressure-sensitive adhesive layer 4 of the laminate 12 shown in FIG. 5.

  FIG. 7 is a schematic sectional view showing a laminate 14 as an example of the surface protection tape of the present invention. The laminate 14 is a laminate in which the shrinkable film layer 2, the elastic layer 31 as the constraining layer 3, the rigid film layer 32, the intermediate layer 6, and the adhesive layer 4 are laminated in this order. By applying the stimulus, the one or two cylindrical wound bodies can be formed by voluntarily winding from one end to one direction or from two opposite ends toward the center. As shown in FIG. 7, the laminate 14 includes the shrinkable film layer 2, the elastic layer 31 and the rigid film layer 32 as the constraining layer 3 that restrains the shrinkage of the shrinkable film layer 2, and the intermediate layer 6. The pressure-sensitive adhesive layer 4 is laminated in order.

  The intermediate layer 6 is located between the rigid film layer 32 and the pressure-sensitive adhesive layer 4 and relieves the tensile stress of the composite base material composed of the shrinkable film layer / elastic layer / rigid film layer, thereby making the wafer extremely thin. It has the function of suppressing the warpage of the wafer that occurs during grinding. The mid layer 6 is characterized by exhibiting low elasticity compared to the rigid film layer.

  FIG. 8 is a schematic cross-sectional view showing a laminate 15 as an example of the surface protection tape of the present invention. The laminate 15 shown in FIG. 8 has a shrinkable film layer 2 and an active energy ray-curable pressure-sensitive adhesive layer 33 laminated, and the active energy ray-curable pressure-sensitive adhesive layer 33 is opposite to the shrinkable film layer 2. The release liner 5 is adhered to the surface.

The laminate 15 is preferably cured by irradiating an active energy ray with a shrinkable film layer having shrinkability in at least one axial direction, and a product of tensile elastic modulus and thickness at 80 ° C. is 5 × 10 ^3. It has a structure in which an active energy ray-curable pressure-sensitive adhesive layer that is N / m or more and less than 1 × 10 ⁵ N / m is laminated, and two ends that are opposite to each other in one direction from one end by applying heat One or two cylindrical wound bodies can be formed by voluntarily winding from the portion toward the center. Further, between the shrinkable film layer and the active energy ray-curable pressure-sensitive adhesive layer, there may be another layer within a range that does not impair the spontaneous winding property, but the tensile modulus at 80 ° C. It is preferable not to have a layer having a thickness product of 4 × 10 ⁵ N / m or more (particularly 1 × 10 ⁵ N / m or more).

[Shrinkable film layer]
The shrinkable film layer 2 may be any film layer that has shrinkability in at least one axial direction by applying heat. The shrinkable film layer may be shrinkable only in one axial direction, or has a primary shrinkage in a certain direction (uniaxial direction) and a direction different from the direction (for example, in this direction). It may have secondary contractility in the direction perpendicular to the surface. The shrinkable film layer 1 may be a single layer or a multilayer composed of two or more layers.

  The shrinkage rate in the main shrinkage direction of the shrinkable film layer 2 is, for example, 5 to 90%, preferably 30 to 90%, particularly preferably 50 to 50% at a predetermined temperature in the range of 70 to 180 ° C (eg, 80 ° C). 90%. The shrinkage rate in the direction other than the main shrinkage direction of the shrinkable film layer constituting the shrinkable film layer is preferably 10% or less, more preferably 5% or less, and particularly preferably 3% or less. The heat shrinkability of the shrinkable film layer can be imparted, for example, by subjecting the film extruded by an extruder to a stretching process.

  In the present specification, the shrinkage rate (%) means a value calculated from the formula [(dimension before shrinkage−dimension after shrinkage) / (dimension before shrinkage)] × 100. Unless otherwise indicated, the contraction rate in the main contraction axis direction is shown.

  Examples of the shrinkable film layer 2 include one selected from polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, polynorbornene, polyimide, polyamide, polyurethane, polystyrene, polyvinylidene chloride, and polyvinyl chloride. A uniaxially stretched film made of two or more kinds of resins is exemplified. Among them, a monoaxially stretched film made of a polyester resin, a polyolefin resin (including a cyclic polyolefin resin) such as polyethylene, polypropylene, polynorbornene, or a polyurethane resin is superior in terms of excellent workability of the adhesive. preferable. Such shrinkable film layers include “Space Clean” by Toyobo, “Fancy Wrap” by Gunze, “Trephan” by Toray, “Lumiler” by Toray, and “Arton” by JSR. "Zeonor" manufactured by ZEON Corporation, "Suntec" manufactured by Asahi Kasei Corporation, and other commercial products can be used.

  In the laminate 15, when the active energy ray curable pressure-sensitive adhesive layer 33 is cured, when the active energy ray irradiation is performed through the shrinkable film layer 2, the shrinkable film layer 2 has a predetermined amount or more of active energy rays. It is necessary to configure with a permeable material (for example, a resin having transparency).

  The thickness of the shrinkable film layer 2 is generally 5 to 300 μm, preferably 10 to 100 μm. If the thickness of the shrinkable film layer 2 is too large, the rigidity becomes high and spontaneous winding does not occur, and separation occurs between the shrinkable film layer and the active energy ray-curable pressure-sensitive adhesive layer 33 after irradiation with active energy rays. , Which tends to lead to laminate destruction. In addition, a film having a high rigidity retains stress at the time of tape bonding, has a large elastic deformation force, increases warpage when the wafer is thinned, and tends to break the adherend due to conveyance or the like.

  The surface of the shrinkable film layer 2 is improved by conventional surface treatments such as chromic acid treatment, ozone exposure, flame exposure, high piezoelectric impact exposure, ionizing radiation treatment, etc. in order to improve adhesion and retention with adjacent layers. Chemical or physical treatment, coating treatment with a primer (for example, an adhesive substance, etc.) may be applied.

[Constrained layer]
The constraining layer 3 constrains the shrinkage of the shrinkable film layer 2 and generates a reaction force, thereby creating a couple of forces as a whole of the laminated body, which becomes a driving force that causes winding. In addition, the constraining layer 3 suppresses secondary shrinkage in a direction different from the main shrinkage direction of the shrinkable film layer 2, and the shrinkable film layer is not necessarily uniform even though it is uniaxial shrinkage. It is considered that the contraction direction of 2 converges in one direction. For this reason, when the heat | fever which accelerates | stimulates the shrinkage | contraction of the shrinkable film layer 2 is added to a lamination sheet, the repulsive force with respect to the shrinkage force of the shrinkable film layer 2 in the constraining layer 3 will become a driving force, Part or opposite two ends), and the wound film layer 2 side is wound inward, and is wound spontaneously from the edge part in one direction or the central direction (usually the main shrinkage axis direction of the shrinkable film layer). It is considered that a cylindrical wound body is formed. In addition, since the constraining layer 3 can prevent the shearing force generated by the contraction deformation of the shrinkable film layer 2 from being transmitted to the pressure-sensitive adhesive layer 4 or the adherend, the pressure-sensitive adhesive force during re-peeling is reduced. Damage to the pressure-sensitive adhesive layer (for example, a cured pressure-sensitive adhesive layer), damage to the adherend, and contamination of the adherend due to the damaged pressure-sensitive adhesive layer can be prevented.

  Since the constraining layer 3 expresses a function of constraining the contraction of the shrinkable film layer 2, the constraining layer 3 has elasticity and adhesiveness (including tackiness) to the shrinkable film layer 2. Further, the constraining layer 3 preferably has a certain degree of toughness or rigidity in order to form a cylindrical wound body smoothly. The constraining layer 3 may be composed of a single layer, or may be composed of a plurality of layers in which functions are shared by a plurality of layers. The constraining layer 3 is preferably composed of an elastic layer 31 and a rigid film layer 32.

[Elastic layer]
The elastic layer 31 is under the temperature at the time of contraction of the shrinkable film layer 2 (in the laminate 12 and laminate 13 as the surface protective tape 1, the laminate 11 is used as a support base material for the surface protective tape. 12 and the temperature at the time of peeling of the laminated body 13), it is preferable to be easily deformed, that is, in a rubber state. However, with a fluid material, a sufficient reaction force does not occur, and eventually the shrinkable film layer alone contracts and deformation (spontaneous winding) cannot occur. Therefore, the elastic layer 31 is preferably one in which fluidity is suppressed by three-dimensional crosslinking or the like. Also, the elastic layer 31 is uniform by resisting a weak force component of the non-uniform shrinkage force of the shrinkable film layer 2 and preventing shrinkage deformation due to the weak force component, depending on the thickness thereof. It has the effect | action which converts into a contraction direction. The warp caused by wafer grinding is thought to be caused by the stress when the adhesive sheet is bonded to the wafer, and the shrinkable film layer is elastically deformed by this residual stress, but the elastic layer relaxes this residual stress. It also works to reduce warpage.

  Therefore, it is desirable that the elastic layer 31 is made of a resin having adhesiveness and having a glass transition temperature of, for example, 50 ° C. or lower, preferably room temperature (25 ° C.) or lower, more preferably 0 ° C. or lower. The adhesive force on the surface of the elastic layer 31 on the side of the shrinkable film layer 2 is a value of 180 ° peel peel test (according to JIS Z 0237, tensile speed 300 mm / min, 50 ° C.), preferably 0.5 N / 10 mm or more Range. When this adhesive force is too low, peeling between the shrinkable film layer 2 and the elastic layer 31 tends to occur.

Moreover, the shear modulus G of the elastic layer 31 in the peeling at temperatures from room temperature (25 ° C.) (e.g. ^{80 ℃), 1x10 4 Pa~5x10 6} Pa ( particularly, 0.05x10 ⁶ Pa~3x10 ⁶ Pa) is preferable. If the shear elastic modulus is too small, the effect of converting the shrinkage stress of the shrinkable film layer into the stress necessary for winding is poor, and conversely, if it is too large, the winding property is poor in order to increase rigidity, and generally This is because a material having high elasticity is poor in adhesiveness and is difficult to produce a laminate, and also has a poor function of relieving residual stress. The thickness of the elastic layer 31 is preferably about 15 to 150 μm. If the thickness is too thin, it is difficult to obtain the restraint property against shrinkage of the shrinkable film layer 2 and the effect of stress relaxation is also reduced. On the other hand, if it is too thick, the spontaneous winding property is lowered, and the handling property and the economical property are inferior. Therefore, the product (shear modulus G × thickness) of the shear modulus G (for example, a value at 80 ° C.) and the thickness of the elastic layer 31 is preferably 1 to 1000 N / m (more preferably 1 to 150 N / m, and still more preferably). 1.2 to 100 N / m).

  The elastic layer 31 is formed of a material that easily transmits active energy rays when the pressure-sensitive adhesive layer 4 is an active energy ray-curable pressure-sensitive adhesive layer, and the thickness is appropriately selected from the viewpoint of manufacturing and workability. It is preferable that it can be easily formed into a film shape and has excellent moldability.

  As the elastic layer 31, for example, a foam material (foamed film) such as urethane foam or acrylic foam whose surface (at least the surface on the side of the shrinkable film layer 2) is subjected to adhesion treatment, rubber, thermoplastic elastomer, etc. Resin films (including sheets) such as non-foamed resin films can be used. The pressure-sensitive adhesive used for the pressure-sensitive adhesive treatment is not particularly limited. For example, acrylic pressure-sensitive adhesive, rubber pressure-sensitive adhesive, vinyl alkyl ether pressure-sensitive adhesive, silicone pressure-sensitive adhesive, polyester pressure-sensitive adhesive, polyamide pressure-sensitive adhesive, urethane type Known pressure-sensitive adhesives such as pressure-sensitive adhesives and styrene-diene block copolymer-based pressure-sensitive adhesives can be used alone or in combination of two or more. In particular, an acrylic pressure-sensitive adhesive is preferably used from the viewpoint of adjusting the adhesive strength. In addition, the resin of the adhesive used for the adhesion treatment and the resin of the foamed film or the non-foamed resin film are preferably the same type of resin in order to obtain high affinity. For example, when an acrylic pressure-sensitive adhesive is used for the adhesion treatment, acrylic foam or the like is suitable as the foam material.

  Moreover, you may form as the elastic layer 31 with the resin composition which has adhesiveness itself, such as a crosslinkable ester-type adhesive, a crosslinkable acrylic adhesive, for example. Such a layer (adhesive layer) formed of a cross-linked ester-based pressure-sensitive adhesive, a cross-linked acrylic pressure-sensitive adhesive, etc. can be produced by a relatively simple method without the need for a separate pressure-sensitive treatment. It is preferably used because of its excellent properties and economy.

  The cross-linked ester pressure-sensitive adhesive has a configuration in which a cross-linking agent is added to an ester pressure-sensitive adhesive having an ester polymer as a base polymer. Examples of the ester-based polymer include polyester made of a condensation polymer of diol and dicarboxylic acid.

  Examples of the diol include (poly) carbonate diol. Examples of (poly) carbonate diol include (poly) hexamethylene carbonate diol, (poly) 3-methyl (pentamethylene) carbonate diol, (poly) trimethylene carbonate diol, and copolymers thereof. A diol component or (poly) carbonate diol can be used individually or in combination of 2 or more types. In addition, when (poly) carbonate diol is polycarbonate diol, the polymerization degree is not particularly limited.

  As a commercial item of (poly) carbonate diol, for example, trade name “PLACCEL CD208PL”, trade name “PLACCEL CD210PL”, trade name “PLACCEL CD220PL”, trade name “PLACCEL CD208”, trade name “PLACCEL CD210”, trade name “PLACCEL CD220”, trade name “PLACCEL CD208HL”, trade name “PLACELCD210HL”, trade name “PLACCEL CD220HL” [manufactured by Daicel Chemical Industries, Ltd.], and the like.

  As the diol component, in addition to (poly) carbonate diol, components such as ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, and octadecanediol may be used in combination.

  Moreover, as a dicarboxylic acid component, the dicarboxylic acid component which contains dicarboxylic acid which has a C2-C20 aliphatic or alicyclic hydrocarbon group as a molecular skeleton, or its reactive derivative as an essential component can be used suitably. . In the dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms or a reactive derivative thereof, the hydrocarbon group may be linear or branched. Also good. Representative examples of such dicarboxylic acids or reactive derivatives thereof include succinic acid, methyl succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid. , Tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, and acid anhydrides and lower alkyl esters thereof. The dicarboxylic acid components can be used alone or in combination of two or more.

  As a combination of diol and dicarboxylic acid, polycarbonate diol and sebacic acid, or adipic acid, pimelic acid, suberic acid, azelaic acid, phthalic acid, maleic acid and the like can be preferably used.

The cross-linked acrylic pressure-sensitive adhesive has a configuration in which a cross-linking agent is added to an acrylic pressure-sensitive adhesive having an acrylic polymer as a base polymer. Examples of the acrylic polymer include (meth) methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, and the like. homo- or copolymer of (meth) acrylic acid alkyl esters such as acrylic acid C ₁ -C ₂₀ alkyl ester; the (meth) acrylic acid alkyl ester, other copolymerizable monomers [for example, acrylic acid, methacrylic acid, Carboxyl group or acid anhydride group-containing monomer such as itaconic acid, fumaric acid, maleic anhydride; hydroxyl group-containing monomer such as 2-hydroxyethyl (meth) acrylate; amino group-containing monomer such as morpholyl (meth) acrylate; Amide group-containing monomers such as (meth) acrylamide; (meth) acrylonitrile Like copolymer of (meth) having an alicyclic hydrocarbon group such as isobornyl acrylate (meth) acrylic acid esters]; cyano group-containing monomers such as.

As the acrylic polymer, in particular, one or more of (meth) acrylic acid C ₁ -C ₁₂ alkyl esters such as ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate, and hydroxyl such as 2-hydroxyethyl acrylate A copolymer with at least one copolymerizable monomer selected from a group-containing monomer and a carboxyl group or an acid anhydride group-containing monomer such as acrylic acid, or 1 of a (meth) acrylic acid C ₁ -C ₁₂ alkyl ester One or more species, (meth) acrylic acid ester having an alicyclic hydrocarbon group, at least one copolymerizable monomer selected from a hydroxyl group-containing monomer and a carboxyl group or an acid anhydride group-containing monomer; These copolymers are preferred.

  The acrylic polymer is prepared as a high-viscosity liquid prepolymer by, for example, polymerizing the above-exemplified monomer components (and polymerization initiator) without solvent (such as ultraviolet rays). Next, a crosslinked acrylic pressure-sensitive adhesive composition can be obtained by adding a crosslinking agent to the prepolymer. In addition, you may add a crosslinking agent at the time of prepolymer manufacture. Further, by adding a crosslinking agent and a solvent (not necessarily required when using a solution of an acrylic polymer) to the acrylic polymer obtained by polymerizing the monomer components exemplified above or a solution thereof, A crosslinked acrylic pressure-sensitive adhesive composition can also be obtained.

  The crosslinking agent is not particularly limited. For example, an isocyanate crosslinking agent, a melamine crosslinking agent, an epoxy crosslinking agent, an acrylate crosslinking agent (polyfunctional acrylate), a (meth) acrylic acid ester having an isocyanate group, or the like is used. it can. Examples of the acrylate crosslinking agent include hexanediol diacrylate, 1,4-butanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and the like. Examples of the (meth) acrylic acid ester having an isocyanate group include 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate. Especially, as a crosslinking agent, ultraviolet (UV) reactive crosslinking agents, such as an acrylate type crosslinking agent (polyfunctional acrylate) and (meth) acrylic acid ester which has an isocyanate group, are preferable. The addition amount of the crosslinking agent is usually about 0.01 to 150 parts by weight, preferably about 0.05 to 50 parts by weight, particularly preferably about 0.05 to 30 parts by weight with respect to 100 parts by weight of the base polymer. is there.

  In addition to the base polymer and the crosslinking agent, the crosslinked acrylic pressure-sensitive adhesive is a crosslinking accelerator, a tackifier (for example, rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin, etc.), thickener, plasticizer In addition, an appropriate additive such as a filler, an anti-aging agent and an antioxidant may be contained.

  The crosslinkable acrylic pressure-sensitive adhesive layer as the elastic layer 31 has a desired thickness and area by, for example, a crosslinkable acrylic pressure-sensitive adhesive composition obtained by adding a crosslinker to the prepolymer by a known method such as a casting method. The elastic layer 31 suitable for the purpose can be easily obtained by forming the film shape and irradiating light again to advance the crosslinking reaction (and polymerization of the unreacted monomer). Since the elastic layer (crosslinked acrylic pressure-sensitive adhesive layer) thus obtained has self-adhesiveness, it can be used by directly bonding between the shrinkable film layer 2 and the rigid film layer 32. A commercially available double-sided adhesive tape such as “HJ-9150W” manufactured by Nitto Denko Corporation can be used as the cross-linked acrylic pressure-sensitive adhesive layer. In addition, after bonding a film-like adhesive between the shrinkable film layer 2 and the rigid film layer 32, you may perform a crosslinking reaction by irradiating light again.

  The cross-linked acrylic pressure-sensitive adhesive layer as the elastic layer 31 is formed by coating the surface of the rigid film layer 32 with the cross-linked acrylic pressure-sensitive adhesive composition in which the acrylic polymer and the cross-linking agent are dissolved in a solvent. Further, it can also be obtained by irradiating with light after the shrinkable film layer 2 is bonded thereto. When the pressure-sensitive adhesive layer 4 is an active energy ray-curable pressure-sensitive adhesive layer, the cross-linked acrylic pressure-sensitive adhesive is irradiated by active energy ray irradiation (light irradiation) when the pressure-sensitive adhesive layer 4 is cured during re-peeling. The agent may be cured (crosslinked).

  Beads such as glass beads and resin beads may be further added to the constituent components of the elastic layer 31 in the present invention. Addition of glass beads or resin beads to the elastic layer 31 is advantageous in that the adhesive properties and shear modulus can be easily controlled. The average particle diameter of the beads is, for example, about 1 to 100 μm, preferably about 1 to 20 μm. The amount of beads added is, for example, 0.1 to 10 parts by weight, preferably 1 to 4 parts by weight, based on 100 parts by weight of the entire elastic layer 31. If the addition amount is too large, the adhesive properties may be deteriorated. If the addition amount is too small, the above-mentioned effect tends to be insufficient.

[Rigid film layer]
The rigid film layer 32 has a function of generating a reaction force with respect to the shrinkage force of the shrinkable film layer 2 by giving rigidity or toughness to the constraining layer 3 and thus generating a couple force necessary for winding. By providing the rigid film layer 32, when the shrinkable film layer 2 is given a stimulus that causes shrinkage such as heating, the laminated sheet or the adhesive sheet is smoothly stopped without stopping or deviating in the direction. It is possible to form a cylindrical wound body that is self-wound and is well-shaped.

  Examples of the rigid film constituting the rigid film layer 32 include polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polyimides; polyamides; polyurethanes; styrene resins such as polystyrene; Vinylidene; a film made of one or more resins selected from polyvinyl chloride and the like can be mentioned. Of these, a polyester resin film, a polypropylene film, a polyamide film, and the like are preferable from the viewpoint of excellent coating workability of the pressure-sensitive adhesive. The rigid film layer 32 may be a single layer or a multilayer in which two or more layers are laminated. The rigid film constituting the rigid film layer 32 is non-shrinkable, and the shrinkage rate is, for example, 5% or less, preferably 3% or less, and more preferably 1% or less.

The product of Young's modulus and thickness (Young's modulus × thickness) of the rigid film layer 32 is preferably 3.0 × 10 ⁵ N / m or less (eg, 1.0 × 10 ² ) at the peeling temperature (eg, 80 ° C.). To 3.0 × 10 ⁵ N / m), more preferably 2.8 × 10 ⁵ N / m or less (for example, 1.0 × 10 ^{3 to} 2.8 × 10 ⁵ N / m). If the product of the Young's modulus and the thickness of the rigid film layer 32 is too small, the effect of converting the shrinkage stress of the shrinkable film layer 2 into a winding stress is poor, and the directional convergence action tends to be reduced. Winding is easily suppressed by rigidity. The Young's modulus of the rigid film layer 32 is preferably 3 × 10 ⁶ to 2 × 10 ¹⁰ N / m ² , more preferably 1 × 10 ⁸ to 1 × 10 ¹⁰ N / m at the peeling temperature (for example, 80 ° C.). ² . If the Young's modulus is too small, it is difficult to obtain a cylindrical wound body with a well-formed shape. Conversely, if the Young's modulus is too large, spontaneous winding is difficult to occur. The thickness of the rigid film layer 32 is, for example, about 20 to 150 μm, preferably 25 to 95 μm, more preferably 30 to 90 μm, and particularly preferably about 30 to 80 μm. If the thickness is too thin, it is difficult to obtain a rolled cylindrical wound body having a well-formed shape, and if it is too thick, the spontaneous winding property is deteriorated, and the handling property and economical efficiency are inferior.

  The rigid film layer 32 is formed of a material that easily transmits active energy rays when the pressure-sensitive adhesive layer 4 is an active energy ray-curable pressure-sensitive adhesive layer, and has an appropriate thickness from the viewpoint of manufacturing and workability. It is preferable that the film can be selected and is excellent in moldability that can be easily formed into a film shape.

  In the above example, the constraining layer 3 is composed of the elastic layer 31 and the rigid film layer 32, but such a configuration is not necessarily required. For example, moderate rigidity can be given to the elastic layer 31 and the rigid film layer 32 can be omitted.

[Adhesive layer]
As the pressure-sensitive adhesive layer 4, a pressure-sensitive adhesive layer having a low adhesive force can be originally used. However, the pressure-sensitive adhesive layer 4 has adhesiveness that can be attached to an adherend, and after a predetermined role is finished, some method ( A re-peelable pressure-sensitive adhesive layer capable of reducing or eliminating the pressure-sensitive adhesiveness in the low-tackifying treatment) is preferable. Such a removable pressure-sensitive adhesive layer can be configured in the same manner as the pressure-sensitive adhesive layer of a known removable pressure-sensitive adhesive sheet. From the viewpoint of spontaneous rollability, the adhesive strength of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive layer after the low-adhesion treatment (180 ° peel peeling, silicon mirror wafer, pulling speed 300 mm / min) is, for example, at room temperature (25 ° C.). 6.5 N / 10 mm or less (especially 6.0 N / 10 mm or less).

  As the pressure-sensitive adhesive layer 4, an active energy ray-curable pressure-sensitive adhesive layer can be preferably used. The active energy ray-curable pressure-sensitive adhesive layer has an adhesive property at an early stage, and forms a three-dimensional network structure by irradiation with active energy rays such as infrared rays, visible rays, ultraviolet rays, X-rays, and electron beams. An elastic material can be used, and an active energy ray-curable adhesive or the like can be used as such a material. The active energy ray-curable pressure-sensitive adhesive contains a compound obtained by chemically modifying an active energy ray reactive functional group for imparting active energy ray curability, or an active energy ray curable compound (or active energy ray curable resin). To do. Therefore, the active energy ray-curable pressure-sensitive adhesive contains a base material chemically modified with an active energy ray-reactive functional group or an active energy ray-curable compound (or active energy ray-curable resin) in the base material. Those composed of the prepared composition are preferably used.

  As the base material, for example, a conventionally known pressure-sensitive adhesive such as a pressure-sensitive adhesive (pressure-sensitive adhesive) can be used. As the adhesive, for example, rubber polymers such as natural rubber, polyisobutylene rubber, styrene / butadiene rubber, styrene / isoprene / styrene block copolymer rubber, recycled rubber, butyl rubber, polyisobutylene rubber, and NBR were used as the base polymer. Examples include rubber adhesives; silicone adhesives; acrylic adhesives, and the like. Among these, an acrylic pressure-sensitive adhesive is preferable. The base material may be composed of one kind or two or more kinds of ingredients.

Examples of the acrylic pressure-sensitive adhesive include (meth) acrylic such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl (meth) acrylate. homo- or copolymer of (meth) acrylic acid alkyl esters such as acid C ₁ -C ₂₀ alkyl ester; the (meth) acrylic acid alkyl esters with other copolymerizable monomers [for example, acrylic acid, methacrylic acid, itaconic acid , Fumaric acid, maleic anhydride and other carboxyl group or anhydride group-containing monomers; (meth) acrylic acid 2-hydroxyethyl monomers; hydroxyl group-containing monomers (meth) acrylic acid morpholyl-containing monomers; ) Acrylics such as copolymers with amide group-containing monomers such as acrylamide] Acrylic pressure-sensitive adhesive or the like using polymer-based polymer is exemplified. These can be used individually by 1 type or in combination of 2 or more types.

  Active energy ray-reactive functional groups used for chemical modification for curing active energy ray-curable adhesives and active energy ray-curable compounds include infrared rays, visible rays, ultraviolet rays, X-rays, electron beams, etc. Although it will not specifically limit if it can be hardened | cured with this active energy ray, The thing in which the three-dimensional networking (networking) of the active energy ray hardening-type adhesive after irradiation of an active energy ray is made efficient is preferable. These can be used individually by 1 type or in combination of 2 or more types. Examples of the active energy ray-reactive functional group used for the chemical modification include functional groups having a carbon-carbon multiple bond such as acryloyl group, methacryloyl group, vinyl group, allyl group, and acetylene group. These functional groups can form radicals by cleavage of carbon-carbon multiple bonds upon irradiation with active energy rays, and these radicals can form a crosslinking point to form a three-dimensional network structure. Among them, the (meth) acryloyl group can exhibit relatively high reactivity to active energy rays, and can be selected from a wide variety of acrylic adhesives and used in combination. From the viewpoint of sex.

  As a typical example of a base material chemically modified with an active energy ray-reactive functional group, a monomer containing a reactive functional group such as a hydroxyl group or a carboxyl group [for example, 2-hydroxy (meth) acrylate] A reactive functional group-containing acrylic polymer obtained by copolymerizing ethyl, (meth) acrylic acid, etc.] with (meth) acrylic acid alkyl ester (isocyanate group, epoxy group) that reacts with the reactive functional group in the molecule. A polymer obtained by reacting a compound having an active energy ray reactive functional group (acryloyl group, methacryloyl group, etc.) [for example, (meth) acryloyloxyethylene isocyanate etc.].

  The ratio of the monomer containing the reactive functional group in the reactive functional group-containing acrylic polymer is, for example, 5 to 40% by weight, preferably 10 to 30% by weight, based on the total monomers. The amount of the compound having a reactive functional group reactive group and an active energy ray reactive functional group in the molecule when reacting with the reactive functional group-containing acrylic polymer is the reactive functional group-containing acrylic type. It is 50-100 mol% with respect to the reactive functional group (hydroxyl group, carboxyl group, etc.) in a polymer, Preferably it is 60-95 mol%.

  Examples of the active energy ray-curable compound include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4 Examples include compounds having two or more carbon-carbon double bonds such as poly (meth) acryloyl group-containing compounds such as butanediol diacrylate, 1,6-hexanediol diacrylate, and polyethylene glycol diacrylate. These compounds may be used alone or in combination of two or more. Of these, a poly (meth) acryloyl group-containing compound is preferable, and is exemplified in, for example, JP-A No. 2003-292916. Hereinafter, the poly (meth) acryloyl group-containing compound may be referred to as an “acrylate cross-linking agent”.

  As the active energy ray-curable compound, a mixture of an organic salt such as an onium salt and a compound having a plurality of heterocycles in the molecule can also be used. In the mixture, an organic salt is cleaved by irradiation with active energy rays to generate ions, which can be a starting species to cause a ring-opening reaction of a heterocyclic ring to form a three-dimensional network structure. The organic salts include iodonium salts, phosphonium salts, antimonium salts, sulfonium salts, borate salts, etc., and the heterocycles in the compound having a plurality of heterocycles in the molecule include oxirane, oxetane, oxolane. , Thiirane, aziridine and the like. Specifically, compounds described in the Technical Information Association, photocuring technology (2000), and the like can be used.

  Examples of the active energy ray-curable resin include ester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, and acrylic resin (meth) having a (meth) acryloyl group at the molecular end. Photosensitive reactive group-containing polymers such as acrylates, thiol-ene addition type resins having an allyl group at the molecular terminal, photocationic polymerization type resins, cinnamoyl group-containing polymers such as polyvinyl cinnamate, diazotized amino novolak resins and acrylamide type polymers Or an oligomer etc. are mentioned. Furthermore, examples of the polymer that reacts with a high active energy ray include epoxidized polybutadiene, unsaturated polyester, polyglycidyl methacrylate, polyacrylamide, and polyvinylsiloxane. In addition, when using an active energy ray curable resin, the said base material is not necessarily required.

  As the active energy ray-curable pressure-sensitive adhesive, the acrylic polymer or an acrylic polymer chemically modified with an active energy ray-reactive functional group (acrylic having an active energy ray-reactive functional group introduced in the side chain) is used. And a combination of the active energy ray-curable compound (such as a compound having two or more carbon-carbon double bonds) and the like. The combination is preferable from the viewpoint of reactivity and workability because it includes an acrylate group that exhibits relatively high reactivity with active energy rays and can be selected from various acrylic adhesives. Specific examples of such a combination include a combination of an acrylic polymer having an acrylate group introduced into the side chain and a compound having two or more functional groups (particularly acrylate groups) having a carbon-carbon double bond. Can be mentioned. As such a combination, those disclosed in Japanese Patent Application Laid-Open No. 2003-292916 can be used.

  Examples of a method for preparing an acrylic polymer having an acrylate group introduced into the side chain include, for example, an isocyanate compound such as acryloyloxyethyl isocyanate or methacryloyloxyethyl isocyanate on an acrylic polymer containing a hydroxyl group in the side chain. A method of bonding via a urethane bond, or the like can be used.

  The compounding amount of the active energy ray-curable compound is, for example, with respect to 100 parts by weight of the base material (for example, the acrylic polymer or the acrylic polymer chemically modified with the active energy ray-reactive functional group). It is about 0.5 to 200 parts by weight, preferably 5 to 180 parts by weight, and more preferably about 20 to 130 parts by weight.

  The active energy ray-curable pressure-sensitive adhesive is blended with an active energy ray polymerization initiator for curing a compound that imparts active energy ray curability for the purpose of improving the reaction rate for forming a three-dimensional network structure. It may be.

  As the active energy ray polymerization initiator, a known or conventional polymerization initiator can be appropriately selected according to the type of active energy ray to be used (for example, infrared ray, visible ray, ultraviolet ray, X-ray, electron beam, etc.). From the viewpoint of work efficiency, a compound capable of initiating photopolymerization with ultraviolet rays is preferred. Typical active energy ray polymerization initiators include ketone initiators such as benzophenone, acetophenone, quinone, naphthoquinone, anthraquinone, fluorenone; azo initiators such as azobisisobutyronitrile; benzoyl peroxide, perbenzoic acid Examples thereof include, but are not limited to, peroxide-based initiators. Examples of commercially available products include trade names “Irgacure 184” and “Irgacure 651” manufactured by Ciba Geigy.

  An active energy ray polymerization initiator can be used individually or in mixture of 2 or more types. The amount of the active energy ray polymerization initiator is usually about 0.01 to 10 parts by weight, preferably about 1 to 8 parts by weight, based on 100 parts by weight of the base material. In addition, you may use an active energy ray polymerization accelerator together with the said active energy ray polymerization initiator as needed.

  In addition to the above components, the active energy ray-curable pressure-sensitive adhesive has a crosslinking agent, a curing (crosslinking) accelerator, a tackifier, a vulcanizing agent, and a thickening agent in order to obtain appropriate tackiness before and after the active energy ray curing. In order to improve durability, such as an agent, appropriate additives such as an anti-aging agent and an antioxidant are blended as necessary.

  As a preferable active energy ray-curable pressure-sensitive adhesive, for example, a composition in which an active energy ray-curable compound is blended in a base material (pressure-sensitive adhesive), preferably UV curing in which a UV-curable compound is blended in an acrylic pressure-sensitive adhesive. A mold adhesive is used. In particular, as a preferable embodiment of the active energy ray-curable pressure-sensitive adhesive, UV curing including a side-chain acrylate-containing acrylic pressure-sensitive adhesive, an acrylate-based cross-linking agent (poly (meth) acryloyl group-containing compound; polyfunctional acrylate), and an ultraviolet photoinitiator. A mold adhesive is used. The side chain acrylate-containing acrylic pressure-sensitive adhesive means an acrylic polymer having an acrylate group introduced in the side chain, and the same ones as described above can be prepared and used in the same manner. The acrylate-based crosslinking agent is a low molecular compound exemplified above as a poly (meth) acryloyl group-containing compound. As the ultraviolet photoinitiator, those exemplified above as typical active energy ray polymerization initiators can be used.

  In addition, as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 4, an inactive energy ray-curable pressure-sensitive adhesive using the acrylic pressure-sensitive adhesive as a base material can be used. In this case, one having an adhesive strength smaller than the peeling stress when generating the cylindrical wound body can be adapted. For example, a 180 ° peel test using a silicon mirror wafer as an adherend (room temperature) (25 ° C.)) of 6.5 N / 10 mm or less (for example, 0.05 to 6.5 N / 10 mm, preferably 0.2 to 6.5 N / 10 mm), particularly 6.0 N / 10 mm or less (for example, 0 0.05 to 6.0 N / 10 mm, preferably 0.2 to 6.0 N / 10 mm).

As such an inactive energy ray-curable pressure-sensitive adhesive based on an acrylic pressure-sensitive adhesive having a low adhesive strength, (meth) acrylic acid alkyl ester [for example, methyl (meth) acrylate, ethyl (meth) acrylate, (Meth) acrylic acid C ₁ -C ₂₀ alkyl ester such as (meth) butyl acrylate, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid octyl], and a monomer having a reactive functional group [for example, acrylic Carboxyl group or acid anhydride group-containing monomers such as acid, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride; hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate; morpholyl (meth) acrylate, etc. Amino group-containing monomer; amide group-containing monomer such as (meth) acrylamide] and the like A copolymer with other copolymerizable monomer [for example, (meth) acrylic acid ester having a cycloaliphatic hydrocarbon group such as isobornyl (meth) acrylate, acrylonitrile, etc.) used as a reactive functional group. An acrylic pressure-sensitive adhesive that is crosslinked by adding a crosslinking agent capable of reacting with a group [for example, an isocyanate-based crosslinking agent, a melamine-based crosslinking agent, an epoxy-based crosslinking agent, or the like] is preferably used.

  The pressure-sensitive adhesive layer 4 is prepared by, for example, applying a coating solution prepared by adding a pressure-sensitive adhesive, an active energy ray-curable compound, and a solvent as necessary, to the surface of the constraining layer 3 (in the above example, the surface of the rigid film layer 32). ), A method of applying the coating liquid onto an appropriate release liner (release liner) to form an adhesive layer, and transferring (transferring) the adhesive layer onto the constraining layer 3. Can be formed. In the case of transfer, a void (void) may remain at the interface with the constraining layer 3. In this case, a heating and pressurizing process can be performed by an autoclave process or the like, and the voids can be diffused and eliminated. The pressure-sensitive adhesive layer 4 may be either a single layer or multiple layers.

  Beads such as glass beads and resin beads may be further added to the constituent components of the pressure-sensitive adhesive layer 4. When glass beads or resin beads are added to the pressure-sensitive adhesive layer 4, the shear modulus is increased and the adhesive force is easily lowered. The average particle diameter of the beads is, for example, about 1 to 100 μm, preferably about 1 to 20 μm. The amount of beads added is, for example, 25 to 200 parts by weight, preferably 50 to 100 parts by weight, based on 100 parts by weight of the entire pressure-sensitive adhesive layer 4. If the amount is too large, poor dispersion may occur and it may be difficult to apply the pressure-sensitive adhesive. If the amount is too small, the above effect tends to be insufficient.

  The thickness of the pressure-sensitive adhesive layer 4 is generally 10 to 200 μm, preferably 20 to 100 μm, and more preferably 30 to 60 μm. If the thickness is too thin, the adhesive strength is insufficient, so that it is difficult to hold and temporarily fix the adherend, and if it is too thick, it is not economical and the handleability is poor.

  The surface protective tape 1 of the present invention is formed by stacking a shrinkable film layer 2 and a constraining layer 3 (preferably an elastic layer 31 and a rigid film layer 32), and compressing the atmospheric pressure such as a stacking means such as a hand roller or a laminator, or an autoclave. The means can be manufactured by selectively using them according to the purpose. Further, the surface protective tape of the present invention can be obtained by providing the pressure-sensitive adhesive layer 4 on the surface of the constraining layer 3 of the surface protective tape 1 or the constraining layer 3 (or rigid film) provided with the pressure-sensitive adhesive layer 4 on one side in advance. The layer 32) may be manufactured by superposing and laminating the shrinkable film layer 2 (or the shrinkable film layer 2 and the elastic layer 31).

  When the surface protection tape 1 has an active energy ray-curable compound on the side in contact with the adherend 7, the surface protection tape 1 is attached to the adherend 7 and subjected to dicing, and then the surface protection tape 1. Irradiation with active energy rays can be performed on the side of the adherend 7 in contact with the adherend 7 to reduce the adhesive strength. Thereafter, or in addition thereto, heat that causes shrinkage of the shrinkable film layer is applied, from one end of the surface protection tape 1 to one direction (usually the main shrinkage axis direction) or from the opposite two ends toward the center. It can be peeled from the adherend 7 by voluntarily winding (usually in the direction of the main contraction axis) to form one or two cylindrical wound bodies. The application of a stimulus that causes contraction such as heating is preferably performed together with active energy ray irradiation. In addition, when voluntarily winding from one end of the surface protection tape 1 in one direction, one cylindrical wound body is formed (one-way winding peeling), and the two opposite ends of the surface protection tape 1 are opposed to each other. When voluntarily winding from the center toward the center, two cylindrical wound bodies arranged in parallel are formed (two-way winding peeling).

  After the dicing process, for example, when the pressure-sensitive adhesive layer 4 is an active energy ray-curable pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer 4 is irradiated with active energy rays, or thereafter a stimulus that causes contraction such as required heating. When a stimulus that causes shrinkage such as heating is applied to the shrinkable film layer 2 by the applying means, the pressure-sensitive adhesive layer 4 is cured and loses adhesive force, and the shrinkable film layer 2 tends to shrink and deform, thereby protecting the surface. The tape 1 is lifted and the surface protection tape 1 is wound around the outer edge (or two outer edges facing each other). One (or two) cylindrical windings that self-propelled in one direction (or two directions opposite to each other (center direction)) while further winding, depending on the conditions for applying a stimulus that causes contraction such as heating Form a gyrus. Here, the cylindrical wound body includes not only a cylindrical wound body in which both ends of the tape are in contact with each other but also a state in which both ends of the tape are not in contact and a part of the cylinder is opened. At this time, since the contraction direction of the pressure-sensitive adhesive sheet is adjusted by the constraining layer 3, a cylindrical wound body is quickly formed while winding in a uniaxial direction. Therefore, the surface protection tape 1 can be peeled off from the adherend 7 very easily and cleanly.

  When applying a stimulus that causes shrinkage by heating, the heating temperature can be appropriately selected according to the shrinkability of the shrinkable film layer 2. The heating temperature is not particularly limited as long as the upper limit temperature is a temperature at which the object to be cut is wound without being affected, for example, 50 ° C. or higher, preferably 50 ° C. to 180 ° C., more preferably 70 ° C. It can be set to ℃-180 ℃. The active energy ray irradiation and the heat treatment may be performed simultaneously or stepwise. In addition to heating the entire surface of the adherend evenly, the entire surface may be heated in stages, or may be partially heated just to create a peeling trigger. Can be appropriately selected.

[Middle layer]
The material for forming the intermediate layer is not particularly limited. For example, the pressure-sensitive adhesive mentioned in the pressure-sensitive adhesive layer, polyethylene (PE) generally referred to as a resin film, and an ethylene-vinyl alcohol copolymer. (EVA), various soft resins such as ethylene-ethyl acrylate copolymer (EEA), mixed resins of acrylic resins and urethane polymers, graft polymers of acrylic resins and natural rubber, and the like can be used.

Examples of the acrylic monomer that forms the acrylic resin include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate, and (meth) acrylic acid. (Meth) acrylic acid alkyl esters such as 2-ethylhexyl and (meth) acrylic acid C ₁ -C ₂₀ alkyl esters such as octyl (meth) acrylic acid alone or copolymerizable with the (meth) acrylic acid alkyl ester Monomer [for example, it can be used by mixing with a carboxyl group or acid anhydride group-containing monomer such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic anhydride, etc.

  As a material for forming the intermediate layer in the present invention, in particular, a mixed resin of acrylic resin and urethane polymer or a graft polymer of acrylic resin and natural rubber is used in terms of adhesion to the rigid film layer. In particular, a mixed resin of an acrylic resin and a urethane polymer is preferable. The urethane polymer can be produced by a well-known and commonly used method.

  For the purpose of improving the adhesion between the intermediate layer and the rigid film layer, an undercoat layer may be appropriately provided between the intermediate layer and the rigid film layer. In addition, for the purpose of improving the adhesion between the intermediate layer and the pressure-sensitive adhesive layer, the surface of the intermediate layer may be subjected to mat treatment, corona discharge treatment, primer treatment, and crosslinking treatment (for example, using silane) as necessary. Conventional physical or chemical treatment such as chemical cross-linking treatment) can be applied.

  The intermediate layer can be formed by a well-known and conventional method depending on the material form. For example, in the case of exhibiting a solution state, the intermediate layer is applied on the surface of the rigid film layer, on an appropriate release liner (separator). It can be formed by applying a solution to form an intermediate layer and transferring (transferring) it onto the rigid film layer. When using a soft resin or mixed resin as the intermediate layer, a method of extruding and laminating the resin on the rigid film layer, a dry laminate of a resin previously formed into a film, or an adhesive property For example, a method of bonding via an undercoat agent can be used.

The shear modulus at 23 ° C. of the intermediate layer is about 1 × 10 ⁴ Pa to ⁴ × 10 ⁷ Pa, preferably 1 × 10 ^{5 in} terms of ease of bonding of the pressure-sensitive adhesive sheet and workability such as tape cutting. It is about Pa to 2 × 10 ⁷ Pa. If the shear modulus at 23 ° C. is less than 1 × 10 ⁴ Pa, the intermediate layer may protrude from the outer periphery of the wafer due to the wafer grinding pressure, and the wafer may be damaged. Moreover, when the shear modulus at 23 ° C. exceeds 4 × 10 ⁷ Pa, the function of suppressing warpage tends to be reduced.

  The thickness of the intermediate layer is preferably 10 μm or more, and particularly preferably 30 μm or more (particularly 50 μm or more). When the thickness of the intermediate layer is less than 10 μm, it tends to be difficult to effectively suppress wafer warpage due to grinding. In order to maintain grinding accuracy, the thickness of the intermediate layer is preferably less than 150 μm.

  Further, the intermediate layer preferably has not only a function of relieving the tensile stress but also a function of a cushion for absorbing irregularities on the wafer surface during grinding, and the sum of the thicknesses of the intermediate layer and the pressure-sensitive adhesive layer is preferable. Is preferably 30 μm or more (in particular, 50 to 300 μm). On the other hand, if the sum of the thickness of the intermediate layer and the pressure-sensitive adhesive layer is less than 30 μm, the adhesive strength to the wafer tends to be insufficient, and unevenness on the wafer surface cannot be absorbed during bonding. There is a tendency that the wafer edge is easily damaged or chipped. Further, if the sum of the thicknesses of the intermediate layer and the pressure-sensitive adhesive layer exceeds 300 μm, the thickness accuracy is lowered, the wafer is easily damaged during grinding, and the spontaneous winding property tends to be lowered. .

  The product of shear modulus and thickness (shear modulus × thickness) of the intermediate layer is preferably 15000 N / m or less (for example, 0.1 to 15000 N / m), preferably 3000 N / m or less at 23 ° C., for example ( For example, it is about 3 to 3000 N / m), particularly preferably about 1000 N / m or less (for example, about 20 to 1000 N / m). If the product of the shear modulus and thickness of the intermediate layer is too large, it will be difficult to relieve the tensile stress of the composite base material composed of the shrinkable film layer / elastic layer / rigid film layer, and suppress warpage of the wafer due to grinding. Since the unevenness on the surface of the wafer cannot be absorbed due to rigidity due to rigidity, the wafer tends to be damaged during grinding or the wafer edge tends to be chipped. If the product of the shear modulus and thickness of the intermediate layer is too small, the intermediate layer protrudes out of the wafer, and edge chipping and breakage tend to occur. Furthermore, the effect | action which reduces winding property is also brought about.

[Active energy ray-curable adhesive layer]
The active energy ray curable pressure-sensitive adhesive layer 33 is adhered to an adherend before irradiation with active energy rays, and is sufficiently adhesive to protect the adherend from “cracking” and “chip”. After processing, by applying active energy rays such as infrared rays, visible rays, ultraviolet rays, X-rays, electron beams, etc., a three-dimensional network structure is formed and cured, thereby adhering to the adherend. When the shrinkable film layer is shrunk by heat, it can exert an action as a constraining layer that repels the shrinkage. The outer edge part (end part) is lifted up, and the wound film layer side is turned inward, and it is wound up in one direction from the end part or from the opposite two end parts to the center (center of the two end parts). Or form two cylindrical wound bodies It can be.

  As the adhesive that forms the active energy ray-curable pressure-sensitive adhesive layer 33, a compound in which an active energy ray-reactive functional group for imparting active energy ray curability is chemically modified, or an active energy ray-curable compound (or It is preferable to contain at least an active energy ray-curable resin). Therefore, the active energy ray-curable pressure-sensitive adhesive is a base material chemically modified with an active energy ray-reactive functional group and / or an active energy ray-curable compound (or active energy ray-curable resin). What is comprised with the composition mix | blended in is used preferably.

  As said base material, adhesive substances, such as a conventionally well-known pressure sensitive adhesive (adhesive), can be used, for example. As the adhesive, for example, rubber polymers such as natural rubber, polyisobutylene rubber, styrene / butadiene rubber, styrene / isoprene / styrene block copolymer rubber, recycled rubber, butyl rubber, polyisobutylene rubber, and NBR were used as the base polymer. Examples include rubber adhesives; silicone adhesives; acrylic adhesives, and the like. Among these, an acrylic pressure-sensitive adhesive is preferable. The base material may be composed of one kind or two or more kinds of ingredients.

Examples of the acrylic pressure-sensitive adhesive include (meth) acrylic such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl (meth) acrylate. homo- or copolymer of (meth) acrylic acid alkyl esters such as acid C ₁ -C ₂₀ alkyl ester; the (meth) acrylic acid alkyl esters with other copolymerizable monomers [for example, acrylic acid, methacrylic acid, itaconic acid , Fumaric acid, maleic anhydride and other carboxyl group or anhydride group-containing monomers; (meth) acrylic acid 2-hydroxyethyl monomers; hydroxyl group-containing monomers (meth) acrylic acid morpholyl-containing monomers; ) Acrylics such as copolymers with amide group-containing monomers such as acrylamide] Acrylic pressure-sensitive adhesive or the like using polymer-based polymer is exemplified. These can be used individually by 1 type or in combination of 2 or more types.

  Active energy ray reactive functional groups and active energy ray-curable compounds used for chemical modification for curing active energy rays can be cured by active energy rays such as infrared rays, visible rays, ultraviolet rays, X-rays, and electron beams. Although it will not specifically limit if it is a thing, The thing in which three-dimensional reticulation (meshing) is made efficient by active energy ray irradiation is preferable. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the active energy ray-reactive functional group used for the chemical modification include functional groups having a carbon-carbon multiple bond such as acryloyl group, methacryloyl group, vinyl group, allyl group, and acetylene group. These functional groups can form radicals by cleavage of carbon-carbon multiple bonds upon irradiation with active energy rays, and these radicals can form a crosslinking point to form a three-dimensional network structure. Among them, the acryloyl group or methacryloyl group can exhibit relatively high reactivity to active energy rays, and can be selected from a wide variety of acrylic adhesives and used in combination. From the viewpoint of sex.

  As a typical example of a base material chemically modified with an active energy ray-reactive functional group, a monomer containing a reactive functional group such as a hydroxyl group or a carboxyl group [for example, 2-hydroxy (meth) acrylate] A reactive functional group-containing acrylic polymer obtained by copolymerizing ethyl, (meth) acrylic acid, etc.] with (meth) acrylic acid alkyl ester (isocyanate group, epoxy group) that reacts with the reactive functional group in the molecule. A polymer obtained by reacting a compound having an active energy ray reactive functional group (acryloyl group, methacryloyl group, etc.) [for example, (meth) acryloyloxyethylene isocyanate etc.].

  The ratio of the monomer containing the reactive functional group in the reactive functional group-containing acrylic polymer is, for example, 5 to 40% by weight, preferably 10 to 30% by weight, based on the total monomers. The amount of the compound having a reactive functional group reactive group and an active energy ray reactive functional group in the molecule when reacting with the reactive functional group-containing acrylic polymer is the reactive functional group-containing acrylic type. It is 50-100 mol% with respect to the reactive functional group (hydroxyl group, carboxyl group, etc.) in a polymer, Preferably it is 60-95 mol%.

  Examples of the active energy ray-curable compound include trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4 -Compounds having two or more groups containing carbon-carbon double bonds such as acryloyl group and methacryloyl group in the molecule, such as butanediol diacrylate, 1,6-hexanediol diacrylate, and polyethylene glycol diacrylate It is done. These compounds may be used alone or in combination of two or more. Of these, compounds having two or more acryloyl groups and / or methacryloyl groups are preferred, and are exemplified in, for example, JP-A No. 2003-292916.

  As the active energy ray-curable compound, a mixture of an organic salt such as an onium salt and a compound having a plurality of heterocycles in the molecule can be used. In the mixture, an organic salt is cleaved by irradiation with active energy rays to generate ions, which can be a starting species to cause a ring-opening reaction of a heterocyclic ring to form a three-dimensional network structure. The organic salts include iodonium salts, phosphonium salts, antimonium salts, sulfonium salts, borate salts, etc., and the heterocycles in the compound having a plurality of heterocycles in the molecule include oxirane, oxetane, oxolane. , Thiirane, aziridine and the like. Specifically, compounds described in the Technical Information Association, photocuring technology (2000), and the like can be used.

  Examples of the active energy ray-curable resin include an acryloyl group or methacryloyl in a molecule such as ester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, and acrylic resin (meth) acrylate. Polymers or oligomers having a group; thiol-ene addition type resins or photocationic polymerization type resins having an allyl group in the molecule; cinnamoyl group-containing polymers such as polyvinyl cinnamate; photosensitivity such as diazotized amino novolak resin or acrylamide type polymer Reactive reactive group-containing polymer or oligomer. Furthermore, examples of the polymer that reacts with a high active energy ray include epoxidized polybutadiene, unsaturated polyester, polyglycidyl methacrylate, polyacrylamide, and polyvinylsiloxane. In addition, when using an active energy ray curable resin, the said base material is not necessarily required.

  The molecular weight of the active energy ray-curable resin is, for example, less than 5000, preferably about 100 to 3000. When the molecular weight of the active energy ray-curable resin exceeds 5000, for example, compatibility with an acrylic polymer (which is a base material) tends to be reduced.

  As the active energy ray-curable resin, ester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, and melamine (meth) are relatively high reactivity with active energy rays. It is preferable to use an oligomer having an acryloyl group or a methacryloyl group in the molecule such as acrylate and acrylic resin (meth) acrylate.

  There are many options for active energy ray-curable pressure-sensitive adhesives, and it is easy to adjust the elastic modulus before and after irradiation of active energy rays, so the active energy ray reactive functional groups are chemically modified to impart active energy ray curability. And an active energy ray-curable compound (or active energy ray-curable resin) are preferably used in combination, and in particular, an acrylic polymer having a (meth) acryloyl group introduced in the side chain, and a molecule The combination with an oligomer having an acryloyl group or a methacryloyl group inside contains a (meth) acryloyl group that exhibits a relatively high reactivity to active energy rays, and can be selected from a variety of acrylic adhesives. And from the viewpoint of workability. As such a combination, those disclosed in Japanese Patent Application Laid-Open No. 2003-292916 can be used.

  The compounding amount of the active energy ray-curable resin (for example, an oligomer having an acryloyl group or a methacryloyl group in the molecule) is, for example, a base material (for example, an acrylic polymer having a (meth) acryloyl group introduced in the side chain). ) About 0.5 to 200 parts by weight, preferably 5 to 180 parts by weight, and more preferably about 20 to 130 parts by weight with respect to 100 parts by weight.

  The active energy ray-curable pressure-sensitive adhesive is blended with an active energy ray polymerization initiator for curing a compound imparting active energy ray curability for the purpose of improving the reaction rate for forming a three-dimensional network structure. Also good.

  As the active energy ray polymerization initiator, a known or conventional polymerization initiator can be appropriately selected according to the type of active energy ray to be used (for example, infrared ray, visible ray, ultraviolet ray, X-ray, electron beam, etc.). From the viewpoint of work efficiency, a compound capable of initiating photopolymerization with ultraviolet rays is preferred. Typical active energy ray polymerization initiators include ketone initiators such as benzophenone, acetophenone, quinone, naphthoquinone, anthraquinone, and fluorenone; azo initiators such as azobisisobutyronitrile; benzoyl peroxide, perbenzoic acid Examples thereof include, but are not limited to, peroxide-based initiators. Examples of commercially available products include trade names “Irgacure 184” and “Irgacure 651” manufactured by Ciba Japan.

  An active energy ray polymerization initiator can be used individually or in mixture of 2 or more types. The amount of the active energy ray polymerization initiator is usually about 0.01 to 10 parts by weight, preferably about 1 to 8 parts by weight, based on 100 parts by weight of the base material. In addition, you may use an active energy ray polymerization accelerator together with the said active energy ray polymerization initiator as needed.

  Beads such as glass beads and resin beads may be further added to the constituent components of the active energy ray-curable pressure-sensitive adhesive layer. When glass beads or resin beads are added to the active energy ray-curable pressure-sensitive adhesive layer, the shear modulus is increased and the adhesive force is easily lowered. The average particle diameter of the beads is, for example, about 1 to 100 μm, preferably about 1 to 20 μm. The amount of beads added is, for example, 25 to 200 parts by weight, preferably 50 to 100 parts by weight, based on 100 parts by weight of the entire active energy ray-curable pressure-sensitive adhesive layer. If the amount is too large, poor dispersion may occur and it may be difficult to apply the pressure-sensitive adhesive. If the amount is too small, the above effect tends to be insufficient.

  In addition to the above components, the active energy ray-curable pressure-sensitive adhesive has a crosslinking agent, a curing (crosslinking) accelerator, a tackifier, a vulcanizing agent, and a thickening agent in order to obtain appropriate tackiness before and after the active energy ray curing. In order to improve durability, such as an agent, appropriate additives such as an anti-aging agent and an antioxidant are blended as necessary.

  Particularly preferred embodiments of the active energy ray-curable pressure-sensitive adhesive include a side chain (meth) acryloyl group-containing acrylic pressure-sensitive adhesive, an oligomer having an acryloyl group or methacryloyl group in the molecule, and an acrylate-based crosslinking agent (poly (meth) acryloyl group-containing). Compound; polyfunctional acrylate), and a UV curable pressure-sensitive adhesive containing an ultraviolet photoinitiator.

  The active energy ray-curable pressure-sensitive adhesive layer is, for example, a method of applying a coating solution prepared by adding a pressure-sensitive adhesive, an active energy ray-curable compound, and a solvent as necessary, to the surface of the shrinkable film layer. The coating liquid is applied onto a simple release liner (release liner) to form an active energy ray-curable pressure-sensitive adhesive layer, which is then transferred (transferred) onto the shrinkable film layer. it can. In the case of transfer, voids (voids) may remain at the interface with the shrinkable film layer. In this case, a heating and pressurizing process can be performed by an autoclave process or the like, and the voids can be diffused and eliminated. The active energy ray-curable pressure-sensitive adhesive layer may be either a single layer or multiple layers.

  The thickness of the active energy ray-curable pressure-sensitive adhesive layer is generally 10 to 400 μm (for example, 20 to 300 μm), preferably 20 to 200 μm, and more preferably 30 to 100 μm. If the thickness is too thin, the adhesive force is insufficient, so that it is difficult to hold and temporarily fix the adherend, and if it is too thick, it is uneconomical and tends to be inferior in handleability.

  The active energy ray-curable pressure-sensitive adhesive layer 33 has a product of a tensile elastic modulus and a thickness at room temperature (25 ° C.) of about 0.1 to 100 N / m, preferably 0.1 to 20 N / m before irradiation with active energy rays. m is preferable, and the adhesive strength (180 ° peel peeling, silicon mirror wafer, pulling speed 300 mm / min) is preferably in the range of 0.5 N / 10 mm to 10 N / 10 mm at room temperature (25 ° C.), for example. . If the product of the tensile modulus of elasticity and the thickness before irradiation with the active energy ray and the adhesive strength are out of the above ranges, the adhesive strength is insufficient, and it tends to be difficult to hold and temporarily fix the adherend.

The active energy ray-curable pressure-sensitive adhesive layer 33 is cured by irradiation with active energy rays, and the product of the tensile elastic modulus and thickness at 80 ° C. is 5 × 10 ³ N / m or more and 1 × 10 ⁵ N / It is less than m (preferably 8 × 10 ³ N / m or more and less than 1 × 10 ⁵ N / m). When the product of tensile modulus and thickness after irradiation with active energy rays is less than 5 × 10 ³ N / m, sufficient reaction force does not occur, and the entire tape bends due to the shrinkage stress of the heat-shrinkable film. It cannot deform spontaneously and cause spontaneous winding.

Then, by irradiating the active energy ray-curable pressure-sensitive adhesive layer 33 with active energy rays, the product of the tensile elastic modulus and thickness at 80 ° C. is 5 × 10 ³ N / m or more and less than 1 × 10 ⁵ N / m. Therefore, after irradiation with active energy rays, it can have an appropriate toughness or rigidity and can exhibit an action as a constraining layer. With this constraining layer, when the shrinkable film layer is thermally contracted, the contraction is constrained and a reaction force can be generated. For example, the entire laminate 15 in FIG. It can be a driving force.

  Further, secondary shrinkage in a direction different from the main shrinkage direction of the shrinkable film layer 2 is suppressed, and the shrinkage direction of the shrinkable film layer 2 is not necessarily uniform even though it is uniaxial shrinkage. It seems that there is also work to converge in the direction. Therefore, for example, when heat that promotes shrinkage of the shrinkable film layer is applied to the laminate 15 in FIG. 8, the shrinkable film layer in the cured active energy ray-curable pressure-sensitive adhesive layer 33 that exhibits the function as a constraining layer. The repulsive force against the shrinkage force of 2 becomes a driving force, and the outer edge portion (one end portion or two opposite ends) of the laminate 15 is lifted, and the shrinkable film layer 2 side is inward, and the direction from the end portion is one direction. Alternatively, it is considered that the cylindrical wound body is formed by spontaneously winding in the central direction (usually the main shrinkage axis direction of the shrinkable film layer 2).

  Furthermore, the warpage caused by grinding the wafer is considered to be caused by the stress when the adhesive sheet is bonded to the wafer and the shrinkable film layer is elastically deformed by this residual stress. It can also exhibit the effect of reducing the warpage and reducing the warpage. In addition, the cured active energy ray-curable pressure-sensitive adhesive layer 33 that exhibits the function as a constraining layer can prevent shear force generated by shrinkage deformation of the shrinkable film layer from being transmitted to the adherend. The adherend can be prevented from being damaged during peeling. Furthermore, since the active energy ray-curable pressure-sensitive adhesive layer 33 is cured, the adhesive strength to the adherend is significantly reduced, and therefore can be easily peeled off without leaving any adhesive residue on the adherend.

  The surface protection tape of the present invention preferably has the shrinkable film layer 2 and the active energy ray-curable pressure-sensitive adhesive layer 33 overlapped, and is a laminate means such as a hand roller or a laminator, or an atmospheric pressure compression means such as an autoclave. Depending on the case, it can be produced by selectively using and laminating.

  Examples of the active energy rays include infrared rays, visible rays, ultraviolet rays, radiation, and electron beams, and can be appropriately selected according to the type of the active energy ray-curable pressure-sensitive adhesive layer of the surface protection tape to be used. For example, when using a surface protection tape having an ultraviolet curable pressure-sensitive adhesive layer, ultraviolet rays are used as active energy rays.

  The generation method of ultraviolet rays is not particularly limited, and a well-known and common generation method can be adopted. Examples thereof include a discharge lamp method (arc lamp), a flash method, and a laser method. In the present invention, it is preferable to use a discharge lamp method (arc lamp) in terms of excellent industrial productivity, and in particular, an irradiation method using a high-pressure mercury lamp or a metal halide lamp in terms of excellent irradiation efficiency. Is preferably used.

As the wavelength of the ultraviolet ray, a wavelength in the ultraviolet region can be used without any particular limitation, but it is used for general photopolymerization, and the wavelength used in the ultraviolet ray generation method is about 250 to 400 nm. It is preferred to use a wavelength. As the irradiation condition of ultraviolet rays, the polymerization of the pressure-sensitive adhesive constituting the active energy ray-curable pressure-sensitive adhesive layer is started, and the product of the tensile elastic modulus and the thickness at 80 ° C. is 5 × 10 ³ N / m or more and 1 × 10 ^5. What is necessary is just to be able to harden so that it may become less than N / m, and as irradiation intensity, it is about 10-1000 mJ / cm < ² >, for example, Preferably, it is about 50-600 mJ / cm < ² >. When the irradiation intensity of ultraviolet rays is less than 10 mJ / cm ² , the active energy ray-curable pressure-sensitive adhesive layer is not sufficiently cured, and it tends to be difficult to exhibit the function as a constraining layer. On the other hand, when the irradiation intensity exceeds 1000 mJ / cm ² , curing of the active energy ray-curable pressure-sensitive adhesive layer tends to progress excessively and crack.

[Release liner]
In the surface protection tape 1 according to the present invention, from the viewpoint of smoothing and protecting the surface pressure-sensitive adhesive layer 4 or active energy ray-curable pressure-sensitive adhesive layer 33, label processing, blocking prevention, etc., A release liner 5 (separator) may be provided on the surface of the active energy ray-curable pressure-sensitive adhesive layer 33. The release liner 5 is peeled off when being bonded to the adherend, and is not necessarily provided. The release liner 5 to be used is not particularly limited, and a known and commonly used release paper can be used.

  As the release liner 5, for example, a substrate having a release treatment layer, a low adhesive substrate made of a fluorine-based polymer, a low adhesive substrate made of a nonpolar polymer, or the like can be used. As a base material which has the said peeling process layer, the plastic film, paper, etc. which were surface-treated with peeling processing agents, such as a silicone type, a long-chain alkyl type, a fluorine type, and molybdenum sulfide, are mentioned, for example.

  Examples of the fluorine-based polymer in the low adhesive substrate made of the above-mentioned fluorine-based polymer include, for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene / hexafluoropropylene copolymer, Examples include chlorofluoroethylene / vinylidene fluoride copolymer.

  Examples of the nonpolar polymer in the low-adhesive substrate made of the nonpolar polymer include olefin resins (for example, polyethylene, polypropylene, etc.). The release liner can be formed by a known or common method.

  Although it does not specifically limit as thickness of the said release liner 5, For example, it is 10-200 micrometers, Preferably, it is about 25-100 micrometers. Moreover, in order to prevent that an active energy ray hardening-type adhesive layer hardens | cures with environmental ultraviolet rays as needed, the ultraviolet-ray prevention process etc. may be performed to the release liner.

  In FIG. 9, a mode that the surface protection tape of this invention winds spontaneously is shown. In FIG. 9, (A) is a figure which shows the surface protection tape 1 before applying the stimulus which causes shrinkage, such as heat, to a shrinkable film layer, (B) becomes a cause of shrinkage, such as heat, to a shrinkable film layer. Surface protection tape to which irritation was applied (in the case of having an active energy ray-curable pressure-sensitive adhesive layer, the pressure-sensitive adhesive sheet after the active energy ray-curable pressure-sensitive adhesive layer is cured and the adhesive force is reduced) is the outer edge of the sheet ( The figure which shows the state when it starts to wind in one direction (usually the main shrinkage axis direction of a shrinkable film layer) from (one edge part), (C) is one cylindrical winding after the winding of a sheet | seat is complete | finished. It is a figure which shows the state (one direction winding) when a roll is formed. Further, (D) was spontaneously wound from the two opposite ends of the sheet toward the center (usually in the direction of the main shrinkage axis of the shrinkable film layer) to form two cylindrical wound bodies. It is a figure which shows the state (two-way winding) at the time.

  Whether the pressure-sensitive adhesive sheet causes one-way winding or two-way winding, if it has an active energy ray-curable pressure-sensitive adhesive layer, the active energy ray-curable pressure-sensitive adhesive after irradiation with active energy rays It varies depending on the adhesive force of the layer (adhesive layer having a function as a constraining layer) to the shrinkable film layer, the product of the tensile elastic modulus and the thickness, or the like.

  In FIG. 9, L shows the length (usually the main shrinkage axis direction of the shrinkable film layer) of the surface protective tape (the diameter when the sheet is circular) (FIG. 9A), r Indicates the diameter of the formed cylindrical wound body (the maximum diameter when the diameter of the cylindrical wound body is not constant in the length direction of the wound body as in the case where the sheet has a circular shape or the like) (Fig. 9 (C), (D)). In the surface protection tape of this invention, the value of r / L is a value defined by the below-mentioned Example, Preferably it is the range of 0.001-1. Note that L can be, for example, 3 to 2000 mm, preferably 3 to 1000 mm. In addition, the lamination sheet without an adhesive layer shows the same behavior as the adhesive sheet which has an adhesive layer regarding spontaneous winding property.

  The length of the pressure-sensitive adhesive sheet in the direction orthogonal to L can be, for example, about 3 to 2000 mm, preferably about 3 to 1000 mm. The value of r / L constitutes the constraining layer 3 in particular, such as the material type, composition, and thickness of the shrinkable film layer 2, the constraining layer 3 (the elastic layer 31 and the rigid film layer 32), and the pressure-sensitive adhesive layer 4. By adjusting the shear modulus and thickness of the elastic layer 31 and the Young's modulus and thickness of the rigid film layer 32, the above ranges can be obtained. The value of r / L indicates the type, composition, and thickness of each layer of the active energy ray-curable pressure-sensitive adhesive layer in the case where the shrinkable film layer and the active energy ray-curable pressure-sensitive adhesive layer are provided. By adjusting the tensile elastic modulus and thickness of the active energy ray-curable pressure-sensitive adhesive layer (pressure-sensitive adhesive layer having a function as a constraining layer) after irradiation, the above range can be obtained. In this example, the shape of the surface protection tape is a quadrangle, but the shape is not limited to this, and can be appropriately selected according to the purpose, and may be any of a circular shape, an elliptical shape, a polygonal shape, and the like.

  In addition, even if the length L of the sheet | seat winding direction becomes long, the surface protection tape in this invention is wound similarly. Therefore, the diameter r of the cylindrical wound body formed by voluntarily winding when the surface protective tape is contracted by applying a stimulus that causes contraction such as heating, and the winding direction of the surface protective tape The lower limit of the ratio (r / L) to the length L of the sheet decreases as the length L in the winding direction of the sheet increases.

  FIG. 10 shows an example of a state in which the surface protective tape 1 is affixed to the adherend 7 and is diced together with the adherend 7 and then wound spontaneously. As shown in FIG. 10, the surface protection tape 1 becomes a cylindrical wound body having a certain diameter by applying a stimulus that causes contraction such as heating. In addition, when the surface protection tape 1 has an active energy ray hardening-type adhesive layer etc., before the provision of the irritation | stimulation which causes shrinkage, such as heating, or the provision of irritation | stimulation which causes shrinkage, such as heating At the same time, active energy ray irradiation may be performed.

  FIG. 11 shows an example of the flow of chip formation using the surface protective tape of the present invention. First, the surface protective tape is bonded to the adherend (step 41). Subsequently, when the adherend is a semiconductor wafer, back grinding may be performed (step 42). The step 42 may be performed when the adherend is a semiconductor wafer, but may not be performed. Next, a dicing tape / dicing ring is bonded to the surface of the adherend opposite to the surface to which the surface protective tape is applied (step 43). However, the dicing ring may not be bonded.

  Following step 43, dicing is performed (step 44). Next, when a UV curable adhesive is used for the surface protection tape, UV exposure is performed (step 45). Note that UV exposure may not be performed. Subsequently, for example, heating is performed in order to peel the surface protection tape from the adherend by spontaneous winding (step 46). The heating method is not particularly limited, and a hot plate, a heat gun, an infrared lamp or the like can be used as appropriate. Heating may be performed before picking up (each dicing tape) or after picking up. Subsequently, the surface protection tape that has been spontaneously wound and peeled off from the adherend is removed (step 47). Although the removal method is not particularly limited, for example, in addition to removal with a peeling tape, blowing off, sucking, peeling with tweezers, and the like can be mentioned.

  When the surface protection tape of the present invention is used at the time of dicing the adherend, damage to the adherend due to stress at the time of peeling can be avoided, for example, when a fragile adherend such as a thin semiconductor wafer is diced. However, the surface protective tape can be easily peeled and removed from the adherend without damaging or contaminating it.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The shear modulus of the elastic layer and the rigid film layer and the adhesive force of the elastic layer to the shrinkable film were measured as follows. Further, r / L, which is an index for determining whether or not to function as a cylindrical wound body, was defined by the following method.

[Measurement of Young's modulus (80 ° C) of rigid film layer]
The Young's modulus of the rigid film layer was measured by the following method according to JIS K7127. As a tensile tester, Shimadzu Autograph AG-1kNG (with warming hood) was used. A rigid film cut into a length of 200 mm and a width of 10 mm was attached at a chuck distance of 100 mm. After making the atmosphere at 80 ° C. with a heating hood, the sample was pulled at a pulling speed of 5 mm / min to obtain a measured value of the stress-strain correlation. Loads were obtained at two points where the strain was 0.2% and 0.45% to obtain Young's modulus. This measurement was repeated 5 times for the same sample, and the average value was adopted.

[Measurement of shear modulus (80 ° C) of elastic layer]
The shear modulus of the elastic layer was measured by the following method. The elastic layer described in each example and comparative example was produced with a thickness of 1.5 mm to 2 mm, and then punched out with a punch having a diameter of 7.9 mm to obtain a sample for measurement. Using a viscoelastic spectrometer (ARES) manufactured by Rheometric Scientific, the measurement was performed with a chuck pressure of 100 g and a shear frequency of 1 Hz [stainless steel 8 mm parallel plate (manufactured by TIA Instruments, Model 708. 0157)]. And the shear elastic modulus in 80 degreeC was measured.

[Measurement of adhesive strength of elastic layer to shrinkable film]
The adhesive force of the elastic layer to the shrinkable film was measured by a 180 ° peel peel test (50 ° C.). Laminated sheet [A pressure-sensitive adhesive layer (active energy ray-curable pressure-sensitive adhesive layer, non-active energy ray-curable pressure-sensitive adhesive layer) prepared except that a pressure-sensitive adhesive layer is not provided. However, in the case where the elastic layer contains an ultraviolet-reactive crosslinking agent but has not yet been irradiated with ultraviolet rays, the one after irradiation with ultraviolet rays at an intensity of 500 mJ / cm ² ] is cut into a size of 10 mm in width. The surface on the rigid film layer (22 in FIG. 1) side is bonded using a rigid support substrate (silicon wafer) and an adhesive tape, and a tensile jig of a peel peel tester is used on the shrinkable film layer side surface using the adhesive tape. Then, this was placed on a heating stage (heater) at 50 ° C. so that the rigid support substrate was in contact with the heating stage. The tension jig was pulled in the 180 ° direction at a pulling speed of 300 mm / min, and the force (N / 10 mm) when peeling occurred between the shrinkable film layer and the elastic layer was measured. In order to eliminate measurement errors due to differences in the rigid support substrate thickness, the rigid support substrate thickness was standardized as 38 μm.

[Measurement of adhesive strength of non-active energy ray curable adhesive layer to silicon mirror wafer]
A laminate of two types of inactive energy ray-curable pressure-sensitive adhesives obtained in Production Examples 2 and 4 below was bonded to a polyethylene terephthalate substrate (thickness: 38 μm) using a hand roller. This was cut into a width of 10 mm, and after removing the release sheet, it was bonded to a 4-inch mirror silicon wafer (trade name “CZ-N” manufactured by Shin-Etsu Semiconductor Co., Ltd.) with a hand roller. This was bonded to the tension jig of a peel peel tester using an adhesive tape. The tension jig was pulled in the 180 ° direction at a pulling speed of 300 mm / min, and the force (N / 10 mm) when peeling occurred between the shrinkable film layer and the elastic layer was measured.

The active energy ray-curable pressure-sensitive adhesive layers obtained in Production Examples 1 and 3 below were also subjected to a 4-inch mirror silicon wafer (Shin-Etsu) in the same manner as above except that UV exposure was performed at 500 mJ / cm ² before measurement. The adhesive strength with respect to a semiconductor company make, brand name "CZ-N") was measured. As a result, in any of the pressure-sensitive adhesives, the adhesive strength was sufficiently lowered to be peeled at 0.3 N / 10 mm or less. For this reason, in the following examples, description of the adhesive strength of the active energy ray-curable pressure-sensitive adhesive layer to the silicon wafer is omitted.

[Measurement of r / L value]
After the adhesive sheet obtained in the following examples was cut to 100 × 100 mm, those using an active energy ray-curable adhesive were irradiated with ultraviolet rays of about 500 mJ / cm ² . One end of the pressure-sensitive adhesive sheet was immersed in warm water at 80 ° C. along the shrinkage axis direction of the shrink film to promote deformation. About what became a cylindrical winding body, the diameter was calculated | required using the ruler, this value was remove | divided by 100 mm, and it was set as r / L. In addition, the lamination sheet without an adhesive layer shows the same behavior as the adhesive sheet which has an adhesive layer regarding spontaneous winding property.

<Manufacture of adhesive layer>
Production Example 1
[Production of active energy ray-curable pressure-sensitive adhesive layer (1)]
Hydroxyl group derived from 2-hydroxyethyl acrylate of acrylic polymer [composition: obtained by copolymerizing 2-ethylhexyl acrylate: morpholyl acrylate: 2-hydroxyethyl acrylate = 75: 25: 22 (molar ratio)] Was bonded with methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate) to produce an acrylic polymer having a methacrylate group in the side chain.

  15 parts by weight of Aronix M320 (manufactured by Toa Gosei Co., Ltd .; trimethylolpropane PO-modified (n≈2) triacrylate), which is a photopolymerizable crosslinking agent, with respect to 100 parts by weight of the acrylic polymer having a methacrylate group in the side chain , 1 part by weight of a photoinitiator (Ciba Geigy, trade name “Irgacure 651”) and 1 part by weight of an isocyanate-based crosslinking agent (trade name “Coronate L”) are mixed to prepare an active energy ray-curable adhesive. did.

  After coating the obtained active energy ray-curable pressure-sensitive adhesive on a release sheet (trade name “MRF38”, manufactured by Mitsubishi Polyester Film Co., Ltd.) using an applicator, the solvent and other volatiles are dried. A laminated body in which an active energy ray-curable pressure-sensitive adhesive layer having a thickness of 35 μm was provided on a release sheet was obtained.

Production Example 2
[Production of non-active energy ray-curable pressure-sensitive adhesive layer (1)]
Acrylic copolymer [obtained by copolymerizing butyl acrylate: acrylic acid = 100: 3 (weight ratio)] with 100 parts by weight of an epoxy-based cross-linking agent (trade name “Tetrad C, manufactured by Mitsubishi Gas Chemical Company, Inc.) “) 0.7 parts by weight and 2 parts by weight of an isocyanate-based crosslinking agent (trade name“ Coronate L ”) were mixed to prepare a non-energy curable pressure-sensitive adhesive.

  After coating the obtained non-active energy ray-curable adhesive on a release sheet (trade name “MRF38”, manufactured by Mitsubishi Polyester Film Co., Ltd.) using an applicator, the solvent and other volatiles are dried. Thus, a laminate in which an inactive energy ray-curable pressure-sensitive adhesive layer having a thickness of 30 μm was provided on the release sheet was obtained.

Production Example 3
[Production of active energy ray-curable pressure-sensitive adhesive layer (2)]
80% of hydroxyl groups derived from 2-hydroxyethyl acrylate of acrylic polymer [composition: obtained by copolymerizing butyl acrylate: ethyl acrylate: 2-hydroxyethyl acrylate = 50: 50: 20 (weight ratio)] Was combined with methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate) to produce an acrylic polymer having a methacrylate group in the side chain.

  As a compound containing two or more functional groups having a carbon-carbon double bond with respect to 100 parts by weight of the acrylic polymer having a methacrylate group in the side chain, a product name “purple UV1700” 100 manufactured by Nippon Synthetic Chemical Industry Co., Ltd. Active energy ray curable adhesive by mixing 3 parts by weight of a photoinitiator (trade name “Irgacure 184” manufactured by Ciba Geigy Co., Ltd.) and 1.5 parts by weight of an isocyanate-based crosslinking agent (trade name “Coronate L”). An agent was prepared.

  After coating the obtained active energy ray-curable pressure-sensitive adhesive on a release sheet (trade name “MRF38”, manufactured by Mitsubishi Polyester Film Co., Ltd.) using an applicator, the solvent and other volatiles are dried. The laminated body in which the active energy ray hardening-type adhesive layer of thickness 30micrometer was provided on the peeling sheet was obtained.

Production Example 4
[Production of non-active energy ray-curable pressure-sensitive adhesive layer (2)]
Acrylic copolymer [obtained by copolymerizing butyl acrylate: acrylic acid = 100: 3 (weight ratio)] with 100 parts by weight of an epoxy-based cross-linking agent (trade name “Tetrad C, manufactured by Mitsubishi Gas Chemical Company, Inc.) “) 0.7 parts by weight and 2 parts by weight of an isocyanate-based crosslinking agent (trade name“ Coronate L ”) were mixed to prepare a non-energy curable pressure-sensitive adhesive.

  After coating the obtained non-active energy ray-curable adhesive on a release sheet (trade name “MRF38”, manufactured by Mitsubishi Polyester Film Co., Ltd.) using an applicator, the solvent and other volatiles are dried. Thus, a laminate in which an inactive energy ray-curable pressure-sensitive adhesive layer having a thickness of 30 μm was provided on the release sheet was obtained.

Example 1
<Manufacture of protective tape made of shrinkable film layer / constraint layer (elastic layer / rigid film layer) / active energy ray-curable adhesive>
Ester polymer [Product obtained by copolymerizing PLACEL CD220PL: Sebacic acid = 100: 10 (weight ratio) manufactured by Daicel Chemical Industries Ltd.] 100 parts by weight and “Coronate L” (crosslinking agent, manufactured by Nippon Polyurethane Industry Co., Ltd.) A solution prepared by mixing 4 parts by weight and dissolving in ethyl acetate is used as a rigid film layer of polyethylene terephthalate film (PET film, thickness 38 μm: manufactured by Toray Industries, Inc., trade name “Lumirror S105”, one-side easy-printed product) The elastic layer was formed by applying and drying the easy-printed surface. A shrinkable film layer (uniaxially stretched polyester film, thickness 30 μm: manufactured by Toyobo Co., Ltd., trade name “Space Clean S7053”) is layered thereon, laminated using a hand roller, and a laminated sheet (the thickness of the ester adhesive layer) 30 μm) was obtained.

  The active energy ray-curable pressure-sensitive adhesive layer (1) side of the laminate obtained in Production Example 1 was laminated with the rigid film layer side of the laminate sheet obtained above. The obtained laminate was adhered through a laminator, and a shrinkable film layer / constraint layer [elastic layer (ester-based adhesive layer) / rigid film layer (PET film layer)] / active energy ray-curable adhesive (1 ) A protective tape comprising a layer / release sheet was obtained.

<Dicing examination>
The release sheet was peeled off from the obtained protective tape, and the active energy ray-curable adhesive (1) layer side of the protective tape was bonded to the mirror surface (front surface) of the 8-inch silicon mirror wafer with a hand roller. Thereafter, the wafer was ground with a wafer grinding apparatus (DISG, DFG8560) so that the wafer thickness became 200 μm. Next, NBD2170K-X1 (manufactured by Nitto Denko Co., Ltd.) was bonded as a dicing tape to the back side of the wafer, which was the ground side, and further bonded to a dicing ring. Thereafter, single-cut dicing was performed with a dicing apparatus (manufactured by DISCO, DFD651) to cut the wafer into 5 × 5 mm pieces (the protective tape and the wafer were cut at once with one blade).

  Visual inspection after dicing shows that wafers are chipped or cracked even on a single piece, or that the cleaning tape / wafer interface has been infiltrated by washing water during dicing, and it is judged good if it is not. did. As a result, the dicing property was judged to be good.

<Peelability test>
The 8-inch silicon mirror wafer with protective tape after dicing is exposed (500 mJ / cm ² , 15 seconds) using a UV exposure machine using a high-pressure mercury lamp as the light source, placed on an adsorption hot plate at 90 ° C., and peelable. A test was conducted. After about 1 minute, the protective tape peeled off while being deformed into a cylindrical wound body on all the diced pieces.

<Recovery / removal of protective tape>
Next, the protective tape was collected and removed from the singulated wafer. The method was performed at the following two points.
(1) Tweezers work Tweezers were held with tweezers so that the wafer surface was not scratched, and the time required to peel all the wafers was measured.
(2) Use of release tape Prepare release tape with double-sided tape (Nitto Denko, N5000) affixed to polyethylene terephthalate cut to the same dimensions as an 8-inch wafer. Then, it was measured what percentage of the separated protective tape can be collected with the release tape.

  As shown in Table 1, the results of collecting the protective tape showed that all the protective tape could be collected in 15 minutes in the tweezers operation of (1). All of the protective tapes were deformed into a cylindrical wound body having substantially the same shape, and the cylindrical wound body had rigidity, so that recovery with tweezers was easy. Also, by the method using the release tape of (2), all the cylindrical wound bodies have almost the same height and are rigid. There was no adhesion leakage and 100% recovery was possible.

The shrinkable film layer has a heat shrinkage rate in the main shrinkage direction of 70% or more at 100 ° C., and the shear modulus (80 ° C.) of the ester-based pressure-sensitive adhesive layer (elastic layer) is 2.88 × 10 ^5. N / m ² , and the product of shear modulus and thickness is 8.64 N / m. The adhesive force (50 ° C.) of the ester-based pressure-sensitive adhesive layer (elastic layer) to the shrinkable film layer was 13 N / 10 mm.

The Young's modulus at 80 ° C. of the PET film layer (rigid film layer) is 3.72 × 10 ⁹ N / m ² , and the product of Young's modulus and thickness is 1.41 × 10 ⁵ N / m. r / L was 0.06.

Example 2
<Manufacture of protective tape comprising shrinkable film layer / constraint layer (elastic layer / rigid film layer) / inactive energy ray curable adhesive>
Ester polymer [Product obtained by copolymerizing PLACEL CD220PL: Sebacic acid = 100: 10 (weight ratio) manufactured by Daicel Chemical Industries Ltd.] 100 parts by weight and “Coronate L” (crosslinking agent, manufactured by Nippon Polyurethane Industry Co., Ltd.) A non-corona treatment of a polyethylene terephthalate film (PET film, thickness 38 μm: manufactured by Toray Industries, Inc., trade name “Lumirror S105, single-sided corona treated product) as a rigid film layer using a solution mixed with 4 parts by weight and dissolved in ethyl acetate. An elastic layer was formed by applying and drying on the surface, and a shrinkable film layer (uniaxially stretched polyester film, thickness 30 μm: manufactured by Toyobo Co., Ltd., trade name “Space Clean S7053”) was layered thereon using a hand roller. It laminated | stacked and the laminated sheet (thickness of an ester adhesive layer 30 micrometers) was obtained.

  The inactive energy ray-curable pressure-sensitive adhesive layer (1) side of the laminate obtained in Production Example 2 was laminated with the rigid film layer side of the laminate sheet obtained above. The obtained laminate is closely adhered through a laminator, and a shrinkable film layer / constraint layer [elastic layer (ester adhesive layer) / rigid film layer (PET film layer)] / inactive energy ray-curable adhesive ( 1) A protective tape comprising a layer / release sheet was obtained.

<Dicing examination>
Using the obtained protective tape, an 8-inch silicon mirror wafer with a protective tape was subjected to single-cut dicing in the same manner as in Example 1. As a result of visual inspection of the 8-inch silicon mirror wafer with the protective tape after dicing in the same manner as in Example 1, it was determined that the dicing property was good.

<Peelability test>
The 8-inch silicon mirror wafer with the protective tape after the dicing was placed on a 90 ° C. adsorption hot plate, and a peelability test was performed. After about 1 minute, the protective tape peeled off while being deformed into a cylindrical wound body on all the diced pieces.

<Recovery / removal of protective tape>
Next, the protective tape was recovered from the separated wafers by the recovery methods (1) and (2) in the same manner as in Example 1.

  As shown in Table 1, the recovery results of the protective tape showed that all the protective tape could be recovered in 15 minutes in the tweezers operation of (1). All of the protective tapes were transformed into a cylindrical wound body having almost the same shape, and the cylindrical wound body had rigidity and was lifted from the wafer, so that it was easy to collect with tweezers. .

  Also, in the recovery of the protective tape by the method using the peeling tape of (2), since all the cylindrical wound bodies have almost the same height and are rigid, the cylinder to the peeling tape There was no adhesion leakage of the wound body, and 100% could be recovered.

The shrinkable film layer has a heat shrinkage rate in the main shrinkage direction of 70% or more at 100 ° C., and the shear modulus (80 ° C.) of the ester-based pressure-sensitive adhesive layer (elastic layer) is 2.88 × 10 ^5. N / m ² , and the product of shear modulus and thickness is 8.64 N / m. The adhesive force (50 ° C.) of the ester-based pressure-sensitive adhesive layer (elastic layer) to the shrinkable film layer was 13 N / 10 mm.

The Young's modulus at 80 ° C. of the PET film layer (rigid film layer) is 3.72 × 10 ⁹ N / m ² , and the product of Young's modulus and thickness is 1.41 × 10 ⁵ N / m. r / L was 0.06.

Comparative Example 1
<Manufacture of protective tape comprising polyolefin substrate / active energy ray-curable adhesive layer>
The active energy ray-curable pressure-sensitive adhesive layer (1) side of the laminate obtained in Production Example 1 was laminated with Trefan (manufactured by Toray Industries, Inc., double-sided corona-treated product, thickness 60 μm). The obtained laminate was closely adhered through a laminator to obtain a protective tape comprising a polyolefin substrate / UV curable adhesive / release sheet.

<Dicing examination>
Using the obtained protective tape, an 8-inch silicon mirror wafer with a protective tape was subjected to single-cut dicing in the same manner as in Example 1. As a result of visual inspection of the 8-inch silicon mirror wafer with the protective tape after dicing in the same manner as in Example 1, it was determined that the dicing property was good.

<Peelability test>
The 8 inch silicon mirror wafer with protective tape after dicing is exposed (500 mJ / cm ² , 15 seconds) using a UV exposure machine with a high-pressure mercury lamp as the light source, placed on a 90 ° C. adsorption hot plate, and peeled off. A sex test was performed. After about 1 minute, the protective tape was irregularly shaped and slightly deformed on the individual pieces, but no peeling occurred visually.

<Recovery of protective tape>
Next, the protective tape was recovered from the separated wafers by the recovery methods (1) and (2) in the same manner as in Example 1.

  As shown in Table 1, the recovery result of the protective tape was difficult because the tweezers of (1) were not completed after 1 hour. Each of the protective tapes was randomly deformed, and the lift from the wafer was insufficient, and recovery with tweezers was difficult.

  Also, in the recovery of the protective tape by the method using the release tape of (2), since the tape was irregularly shaped and slightly deformed, the adhesion to the release tape was insufficient, and only 13% It could not be recovered.

Example 3
<Manufacture of protective tape made of shrinkable film layer / constraint layer (elastic layer / rigid film layer) / active energy ray-curable adhesive>
100 parts by weight of an acrylic polymer (Daiichi Lace Co., Ltd., trade name “Leocoat R1020S”), 10 parts by weight of a pentaerythritol-modified acrylate crosslinking agent (trade name “DPHA40H” manufactured by Nippon Kayaku Co., Ltd.), “Tetrad C” ( 0.25 parts by weight of a cross-linking agent, manufactured by Mitsubishi Gas Chemical Co., Ltd., 2 parts by weight of “Coronate L” (cross-linking agent, manufactured by Nippon Polyurethane Industry), 3 parts by weight of “Irgacure 651” (photoinitiator, manufactured by Ciba Geigy) The polymer solution dissolved in methyl ethyl ketone was applied to and dried on one surface of a polyethylene terephthalate film (PET film, thickness 38 μm: trade name “Lumirror S10” manufactured by Toray Industries, Inc.) as a rigid film layer to form an elastic layer. Furthermore, a shrinkable film layer (uniaxially stretched polyester film, thickness 60 μm: manufactured by Toyobo Co., Ltd., trade name “Space Clean S5630”) is laminated thereon, and laminated using a hand roller, and a laminated sheet (acrylic pressure-sensitive adhesive layer) Of 30 μm) was obtained.

  On the active energy ray-curable pressure-sensitive adhesive layer (2) side of the laminate comprising the active energy ray-curable pressure-sensitive adhesive layer (2) / release sheet obtained in Production Example 3, the rigid film of the laminate sheet obtained above. Laminated with layer side.

  The obtained laminate was adhered through a laminator, and a shrinkable film layer / constraint layer [acrylic pressure-sensitive adhesive layer (elastic layer) / PET film layer (rigid film layer)] / active energy ray-curable pressure-sensitive adhesive (1 ) A protective tape comprising a layer / release sheet was obtained.

Example 4
<Manufacture of protective tape comprising shrinkable film layer / constraint layer (elastic layer / rigid film layer) / inactive energy ray-curable pressure-sensitive adhesive (2)>
A protective tape was prepared in the same manner as in Example 3 except that the active energy ray-curable pressure-sensitive adhesive layer (2) in Example 3 was changed to the non-active energy ray-curable pressure-sensitive adhesive layer (2) obtained in Production Example 4. Got.

In Examples 3 and 4, the heat shrinkage rate of the heat shrinkable film in the main shrinkage direction was 70% or more at 100 ° C. The acrylic adhesive layer (elastic layer) has a shear modulus (80 ° C.) of 0.72 × 10 ⁶ N / m ² , and the product of the shear modulus and thickness is 21.6 N / m. The adhesive force (50 ° C.) of the system pressure-sensitive adhesive layer (elastic layer) to the shrinkable film layer was 4.4 N / 10 mm. The Young's modulus at 80 ° C. of the PET film layer (rigid film layer) was 3.72 × 10 ⁹ N / m ² , and the product of Young's modulus and thickness was 1.41 × 10 ⁵ N / m. r / L was 0.045.

Comparative Example 2
The active energy ray-curable pressure-sensitive adhesive layer (2) side of the laminate obtained in Production Example 3 is placed on the easy-adhesion treated side of a polyethylene terephthalate film (PET film, thickness 50 μm: trade name “Lumirror S105” manufactured by Toray Industries, Inc.). And laminated. The obtained laminate was brought into close contact with a laminator to obtain a protective tape comprising a base film layer / active energy ray-curable pressure-sensitive adhesive layer / release sheet.

Comparative Example 3
In Comparative Example 2, the same protective tape as in Comparative Example 2 was obtained except that the active energy ray-curable pressure-sensitive adhesive layer (2) was changed to the non-active energy ray-curable pressure-sensitive adhesive layer (2) obtained in Production Example 4. It was.

Comparative Example 4
In Comparative Example 2, a polyethylene terephthalate film obtained by subjecting an ethylene vinyl acetate copolymer (Mitsui DuPont, “Evaflex P1007”) to a thickness of 100 μm by extrusion molding was subjected to easy adhesion treatment by corona treatment. A protective tape similar to that of Comparative Example 2 was obtained.

Comparative Example 5
In Comparative Example 2, the same protective tape as in Comparative Example 1 was obtained except that the polyethylene terephthalate film was changed to a film obtained by extruding low molecular weight polyethylene to a thickness of 100 μm and subjected to an easy adhesion treatment by corona treatment. It was.

<Back grinding process>
The protective tapes obtained in Examples 3 and 4 and Comparative Examples 2 to 5 were attached to an 8-inch silicon mirror wafer with a hand roller. Thereafter, back grinding was performed under the following conditions to obtain a laminate of a silicon wafer having a predetermined thickness and a protective tape.
Backgrinding conditions Equipment: Product name “DFG-8560” manufactured by Disco Corporation
Z1 wheel: manufactured by Disco Corporation, trade name “GF-01-SD360-VS-100” # 360 abrasive grain Z2 wheel: manufactured by Disco Corporation, trade name “BGT270IF-01-1-4 / 6-B-K09” # 2000 Abrasive grain Z2 grinding amount: 50μm
Wafer finish thickness: 250 μm

<Dicing tape application process>
Dicing with a hand roller on the surface (silicon wafer side) opposite to the protective tape of the laminate of the silicon wafer obtained in the back grinding process and the protective tapes of Examples 3 and 4 and Comparative Examples 3 to 6 A tape (manufactured by Nitto Denko Corporation, NBD-2170K-X1) was attached, and a sample for dicing was obtained for each laminate.

<Dicing process>
Each dicing sample obtained in the dicing tape attaching step was diced under the following conditions to obtain a chip shape, and a work with a chip was obtained.
Dicing conditions Equipment: Product name “DFD-651” manufactured by Disco Corporation
Dicing blade: NBC-ZH205O-27HEEE manufactured by Disco Corporation
Dicing speed: 80mm / sec
Blade rotation speed: 40000 rpm
Blade height: 50 μm
Cutting water volume: 1L / min
Chip size: 10mm x 10mm

<UV irradiation to protective tape>
Next, with respect to Example 3 and Comparative Examples 2, 4, and 5 using the active energy ray-curable pressure-sensitive adhesive layer, ultraviolet rays were irradiated from the protective tape side under the following conditions.
Ultraviolet irradiation conditions Device: Nitto Seiki Co., Ltd., trade name “NEL UM-810”
UV illuminance: 20 mW / cm ²
UV light intensity: 1000 mJ / cm ²

<Heating / removal of protective tape>
(1) Removal of protective tape with hot air The chip-attached work affixed with the protective tape obtained in Examples 3 and 4 and Comparative Examples 2 to 5 obtained above is placed on the hot plate so that the dicing tape side is in contact with it. Installed and absorbed. The hot plate having an adsorption mechanism with a surface temperature of 60 ° C. was used.

  Next, hot air was applied for 3 minutes at an angle of 45 degrees from the protective tape side so that the surface temperature of the protective tape was 80 ° C. using a dryer (Ishizaki Electric Co., Ltd., Plaget, PJ214A).

  Thereafter, the hot air was stopped, the chip-attached work was removed from the hot plate, and the number of successful peelings of the protective tape was visually counted. The value obtained by dividing [Number of successful peelings] by [Total number of chips on the workpiece with chips] was defined as the success rate of removing the protective tape by hot air.

(2) Removal of protective tape with peeling tape On the hot plate so that the dicing tape side is in contact with the workpiece with chips to which the protective tapes obtained in Examples 3 and 4 and Comparative Examples 2 to 5 obtained above are attached. Installed and adsorbed. The hot plate having an adsorption mechanism with a surface temperature of 60 ° C. was used.

  Next, the temperature of the hot plate was controlled so that the surface temperature of the protective tape was 80 ° C., and left for 3 minutes. Thereafter, a peeling tape (manufactured by Nitto Denko Co., Ltd., trade name “ELP BT-315”) was attached to the surface of the protective tape using a 230 mm, approximately 4 kg hand roller and allowed to stand for 30 seconds, and then the peeling angle was approximately 120 degrees. The film was peeled at a peeling point moving speed of 300 mm / min.

  Thereafter, the work with chips was removed from the hot plate, and the number of successful peelings of the protective tape was visually counted. The value obtained by dividing [Number of Successful Peeling] by [Total Number of Chips on Work with Chips] was defined as the success rate of removal of the protective tape using the peeling tape.

  In Examples 3 and 4 and Comparative Examples 2 to 5, the results of the protective tape removal experiment are shown in Table 2. In Comparative Examples 2 to 5, it was difficult to obtain a trigger for peeling, and the protective tape removal rate was low. In Examples 3 and 4, the protective tape could be completely removed.

DESCRIPTION OF SYMBOLS 1 Surface protection tape 1 'Surface protection tape after a deformation | transformation by provision of irritation | stimulation which causes shrinkage, such as a heating 10-15 Laminated body of an example of a surface protection tape 2 Shrinkable film layer 3 Constrained layer 31 Elastic layer 32 Rigid film layer 33 Active energy ray-curable pressure-sensitive adhesive layer 4 Pressure-sensitive adhesive layer 5 Release liner 6 Intermediate layer 7 Substrate such as wafer 8 Dicing tape 9 Sample for dicing 19 Dicing ring 101 Conventional surface protection tape 101 ′ Heating of conventional example Surface protective tape after deformation 109 Sample for dicing of conventional example

Claims (7)

A surface protection tape for dicing in which a shrinkable film layer having shrinkability in at least one axial direction attached to the surface of the object to be cut and a constraining layer for restraining the shrinkage of the shrinkable film layer is attached. Process,
In a state where the dicing surface protective tape is affixed, the step of collectively cutting the dicing surface protective tape and the object to be cut;
The dicing surface protective tape affixed to the cut surface of the object to be cut is given a stimulus that causes contraction, and is voluntarily wound from one end to one direction or from two opposite ends toward the center. Turn to form a cylindrical wound body, affix a release tape to the cylindrical wound body stuck on the surface of each cut object, and remove the release tape together with the cylindrical wound body A process for peeling and removing the surface protective tape for dicing.   2. The dicing surface according to claim 1, wherein the peeling tape is removed together with the cylindrical wound body after the surface protective tape for dicing on all the cut objects is deformed into a cylindrical wound body. How to remove the protective tape.   The deformed surface protection tape on a part of the cut objects to be cut is deformed into a cylindrical wound body, and then the release tape is removed together with the cylindrical wound body. 2. A method for peeling and removing the surface protective tape for dicing according to 1.   The peeling of the surface protection tape for dicing according to any one of claims 1 to 3, wherein the release tape is attached to the cylindrical wound body attached to the surface of each cut object by a hand roller. Removal method.   The peeling removal method of the surface protection tape for dicing of any one of Claims 1-4 which makes the peeling angle of the said peeling tape 110-180 degree | times, and removes the said peeling tape with the said cylindrical winding body.   The peeling removal of the surface protection tape for dicing according to any one of claims 1 to 5, wherein the peeling tape is removed together with the cylindrical winding body at a peeling point moving speed of the peeling tape of 10 to 350 mm / min. Method.   The surface for dicing according to any one of claims 1 to 6, wherein a stress necessary for rewinding the cylindrical wound body formed by heating at 80 ° C for 30 seconds is 1.3 N / 10 mm or more. How to remove the protective tape.

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